AP computer science midterm

Which of the following best explains how data is transmitted on the Internet? A Data is broken into packets, which are all sent to the recipient in a specified order along the same path. B Data is broken into packets, which can be sent along different paths. C All data is transmitted in a single packet through a direct connection between the sender and the recipient. D Multiple data files are bundled together in a packet and transmitted together.

B Data is broken into packets, which can be sent along different paths.

The variable age is to be used to represent a person's age, in years. Which of the following is the most appropriate data type for age ? A Boolean B number C string D list

B number

A binary number is to be transformed by appending three 0s to the end of the number. For example, 11101 is transformed to 11101000. Which of the following correctly describes the relationship between the transformed number and the original number? A The transformed number is 3 times the value of the original number. B The transformed number is 4 times the value of the original number. C The transformed number is 8 times the value of the original number. D The transformed number is 1,000 times the value of the original number.

C The transformed number is 8 times the value of the original number.

Consider the following code segment. x ←← 25 y ←← 50 z ←← 75 x ←← y y ←← z z ←← x Which of the variables have the value 50 after executing the code segment? A x only B y only C x and z only D x, y, and z

C x and z only

Which of the following are true statements about the data that can be represented using binary sequences? Binary sequences can be used to represent strings of characters. Binary sequences can be used to represent colors. Binary sequences can be used to represent audio recordings. A I only B I and II only C II and III only D I, II, and III

D I, II, and III

To be eligible for a particular ride at an amusement park, a person must be at least 12 years old and must be between 50 and 80 inches tall, inclusive. Let age represent a person's age, in years, and let height represent the person's height, in inches. Which of the following expressions evaluates to true if and only if the person is eligible for the ride? A (age ≥ 12) AND ((height ≥ 50) AND (height ≤ 80)) B (age ≥ 12) AND ((height ≤ 50) AND (height ≥ 80)) C (age ≥ 12) AND ((height ≤ 50) OR (height ≥ 80)) D (age ≥ 12) OR ((height ≥ 50) AND (height ≤ 80))

A (age ≥ 12) AND ((height ≥ 50) AND (height ≤ 80))

Consider the following numeric values. Binary 1011 Binary 1101 Decimal 5 Decimal 12 Which of the following lists the values in order from least to greatest? A Decimal 5, binary 1011, decimal 12, binary 1101 B Decimal 5, decimal 12, binary 1011, binary 1101 C Decimal 5, binary 1011, binary 1101, decimal 12 D Binary 1011, binary 1101, decimal 5, decimal 12

A Decimal 5, binary 1011, decimal 12, binary 1101 B

A group of students take hundreds of digital photos for a science project about weather patterns. Each photo file contains data representing the level of red, green, and blue for each pixel in the photo. The file also contains metadata that describes the date, time, and geographic location where the photo was taken. For which of the following goals would analyzing the metadata be more appropriate than analyzing the data? A Determining the chronological order of the photos B Determining the number of clouds in a particular photo C Determining whether a photo is suitable for printing in black-and-white D Determining whether two photos were taken at the same location on different days

A Determining the chronological order of the photos D Determining whether two photos were taken at the same location on different days

A video-streaming Web site keeps count of the number of times each video has been played since it was first added to the site. The count is updated each time a video is played and is displayed next to each video to show its popularity. At one time, the count for the most popular video was about two million. Sometime later, the same video displayed a seven-digit negative number as its count, while the counts for the other videos displayed correctly. Which of the following is the most likely explanation for the error? A The count for the video became larger than the maximum value allowed by the data type used to store the count. B The mathematical operations used to calculate the count caused a rounding error to occur. C The software used to update the count failed when too many videos were played simultaneously by too many users. D The software used to update the count contained a sampling error when using digital data to approximate the analog count.

A The count for the video became larger than the maximum value allowed by the data type used to store the count.

A student is recording a song on her computer. When the recording is finished, she saves a copy on her computer. The student notices that the saved copy is of lower sound quality than the original recording. Which of the following could be a possible explanation for the difference in sound quality? A The song was saved using fewer bits per second than the original song. B The song was saved using more bits per second than the original song. C The song was saved using a lossless compression technique. D Some information is lost every time a file is saved from one location on a computer to another location.

A The song was saved using fewer bits per second than the original song.

The question below uses a robot in a grid of squares. The robot is represented as a triangle, which is initially in the center square and facing toward the top of the grid. The following code segment is used to move the robot in the grid. count ←← 1 REPEAT 4 TIMES { REPEAT count TIMES { MOVE_FORWARD() } ROTATE_LEFT() count ←← count + 1 } Which of the following code segments will move the robot from the center square along the same path as the code segment above?

A count ←← 0 REPEAT 4 TIMES { count ←← count + 1 REPEAT count TIMES { MOVE_FORWARD() } ROTATE_LEFT() }

Consider the following code segment. First<--- 100 Second<--- 200 Temp<--- First Second<--- Temp First<--- Second What are the values of first and second as a result of executing the code segment? A first = 100, second = 100 B first = 100, second = 200 C first = 200, second = 100 D first = 200, second = 200

A first = 100, second = 100

The figure below represents a network of physically linked devices labeled A through I. A line between two devices indicates that the devices can communicate directly with each other. Any information sent between two devices that are not directly connected must go through at least one other device. For example, in the network represented below, information can be sent directly between A and B, but information sent between devices A and G must go through other devices. What is the minimum number of connections that must be broken or removed before device B can no longer communicate with device C? A Three B Four C Five D Six

B 4

A company delivers packages by truck and would like to minimize the length of the route that each driver must travel in order to reach nn delivery locations. The company is considering two different algorithms for determining delivery routes. Algorithm I-Generate all possible routes, compute their lengths, and then select the shortest possible route. This algorithm does not run in reasonable time. Algorithm II-Starting from an arbitrary delivery location, find the nearest unvisited delivery location. Continue creating the route by selecting the nearest unvisited location until all locations have been visited. This algorithm does not guarantee the shortest possible route and runs in time proportional to n2n2. Which of the following best categorizes algorithm II? A Algorithm II attempts to use an algorithmic approach to solve an otherwise undecidable problem. B Algorithm II uses a heuristic approach to provide an approximate solution in reasonable time. C Algorithm II provides no improvement over algorithm I because neither algorithm runs in reasonable time. D Algorithm II requires a much faster computer in order to provide any improvement over algorithm I.

B Algorithm II uses a heuristic approach to provide an approximate solution in reasonable time.

Which of the following best explains what happens when a new device is connected to the Internet? A A device driver is assigned to the device. B An Internet Protocol (IP) address is assigned to the device. C A packet number is assigned to the device. D A Web site is assigned to the device.

B An Internet Protocol (IP) address is assigned to the device.

Which of the following best explains how an analog audio signal is typically represented by a computer? A An analog audio signal is measured as input parameters to a program or procedure. The inputs are represented at the lowest level as a collection of variables. B An analog audio signal is measured at regular intervals. Each measurement is stored as a sample, which is represented at the lowest level as a sequence of bits. C An analog audio signal is measured as a sequence of operations that describe how the sound can be reproduced. The operations are represented at the lowest level as programming instructions. D An analog audio signal is measured as text that describes the attributes of the sound. The text is represented at the lowest level as a string.

B An analog audio signal is measured at regular intervals. Each measurement is stored as a sample, which is represented at the lowest level as a sequence of bits.

Internet protocol version 6 (IPv6) has been introduced to replace the previous version (IPv4). Which of the following best describes a benefit of IPv6 over IPv4? A IPv6 addresses are shorter than IPv4 addresses, which allows for faster routing of packets. B IPv6 allows for a greater number of addresses than IPv4, which allows more devices to be connected to the Internet. C IPv6 eliminates the use of hierarchy in addressing, making addresses easier to use. D IPv6 allows users to bypass older security protocols so that data can be sent peer-to-peer without the use of routers.

B IPv6 allows for a greater number of addresses than IPv4, which allows more devices to be connected to the Internet.

A city maintains a database of all traffic tickets that were issued over the past ten years. The tickets are divided into the following two categories. Moving violations Nonmoving violations The data recorded for each ticket include only the following information. The month and year in which the ticket was issued The category of the ticket Which of the following questions CANNOT be answered using only the information in the database?

B In the past ten years, were nonmoving violations more likely to occur on a weekend than on a weekday?

Which of the following statements about the Internet is true? A The Internet is a computer network that uses proprietary communication protocols. B The Internet is designed to scale to support an increasing number of users. C The Internet requires all communications to use encryption protocols. D The Internet uses a centralized system to determine how packets are routed.

B The Internet is designed to scale to support an increasing number of users.

A program developed for a Web store represents customer account balances using a format that approximates real numbers. While testing the program, a software developer discovers that some values appear to be mathematically imprecise. Which of the following is the most likely cause of the imprecision? A The account balances are represented using a fixed number of bits, resulting in overflow errors. B The account balances are represented using a fixed number of bits, resulting in round-off errors. C The account balances are represented using an unlimited number of bits, resulting in overflow errors. D The account balances are represented using an unlimited number of bits, resulting in round-off errors.

B The account balances are represented using a fixed number of bits, resulting in round-off errors.

Directions: For the question or incomplete statement below, two of the suggested answers are correct. For this question, you must select both correct choices to earn credit. No partial credit will be earned if only one correct choice is selected. Select the two that are best in each case. Which of the following can be represented by a single binary digit? Select two answers. A The position of the minute hand of a clock B The remainder when dividing a whole number by 2 C The value of a Boolean variable D The volume of a car radio

B The remainder when dividing a whole number by 2 C The value of a Boolean variable

RunRoutr is a fitness tracking application for smartphones that creates suggested running routes so that users can run with each other. Upon downloading the application, each user creates a username, a personal profile, and a contact list of friends who also use the application. The application uses the smartphone's GPS unit to track a user's location, running speed, and distance traveled. Users can use the application to review information and statistics about their previous runs. At the beginning of a run, users indicate the distance they want to run from their current location, and the application suggests a running route. Once a user accepts a suggested route, the application shares the suggested route with other compatible users in the area so that they can run together. Users are considered compatible if they are on each other's contact lists or if they typically run at similar speeds. A basic RunRoutr account is free, but it displays advertisements that are targeted to individual users based on data collected by the application. For example, if a user's running route begins or ends near a particular store, the application may display an advertisement for that store. Users have the ability to pay a monthly fee for a premium account, which removes advertisements from the application. Which of the following is most likely to be a data privacy concern for RunRoutr users?

B Users of the application may have the ability to determine information about the locations of users that are not on their contact lists.

A game is played by moving a game piece left or right along a horizontal game board. The board consists of spaces of various colors, as shown. The circle represents the initial location of the game piece. The following algorithm indicates how the game is played. The game continues until the game is either won by landing on the red space or lost when the piece moves off either end of the board. Step 1:Place a game piece on a space that is not red and set a counter to 0.Step 2:If the game piece is on a yellow space, move the game piece 3 positions to the left and go to step 3. Otherwise, if the game piece is on a black space, move the game piece 1 position to the left and go to step 3. Otherwise, if the game piece is on a green space, move the game piece 2 positions to the right and go to step 3.Step 3:Increase the value of the counter by 1.Step 4:If game piece is on the red space or moved off the end of the game board, the game is complete. Otherwise, go back to step 2. If a game is begun by placing the game piece on the rightmost black space for step 1, what will be the value of the counter at the end of the game? A 2 B 3 C 4 D 5

C 4

A store uses binary numbers to assign a unique binary sequence to each item in its inventory. What is the minimum number of bits required for each binary sequence if the store has between 75 and 100 items in its inventory? A 5 B 6 C 7 D 8

C 7

The grid below contains a robot represented as a triangle, initially facing toward the top of the grid. The robot can move into a white or gray square but cannot move into a black region. The code segment below uses the procedure goalReached, which evaluates to true if the robot is in the gray square and evaluates to false otherwise. REPEAT UNTIL(goalReached()) { <MISSING CODE> } Which of the following replacements for <MISSING CODE> can be used to move the robot to the gray square? A IF(CAN_MOVE(left)) { ROTATE_LEFT() MOVE_FORWARD() } B IF(CAN_MOVE(forward)) { MOVE_FORWARD() ROTATE_LEFT() } C IF(CAN_MOVE(left)) { ROTATE_LEFT() } MOVE_FORWARD() D IF(CAN_MOVE(forward)) { MOVE_FORWARD() } ELSE { ROTATE_LEFT() }

C IF(CAN_MOVE(left)) { ROTATE_LEFT() } MOVE_FORWARD()

The figure below represents a network of physically linked devices labeled A through I. A line between two devices indicates that the devices can communicate directly with each other. Any information sent between two devices that are not directly connected must go through at least one other device. For example, in the network represented below, information can be sent directly between A and B, but information sent between devices A and G must go through other devices. Which of the following statements is true about the network? A Information sent from device A to device D can use at most two unique paths. B Information sent from device A to device I will pass through at most four other devices. C If devices B and F fail, then device A will not be able to communicate with device G. D If devices C and F fail, then device D will not be able to communicate with device H.

C If devices B and F fail, then device A will not be able to communicate with device G.

Assume that the Boolean variable hot is assigned the value true and the Boolean variable humid is assigned the value false. Which of the following will display the value true ? Select two answers.

C If hot or humid display hot

RunRoutr is a fitness tracking application for smartphones that creates suggested running routes so that users can run with each other. Upon downloading the application, each user creates a username, a personal profile, and a contact list of friends who also use the application. The application uses the smartphone's GPS unit to track a user's location, running speed, and distance traveled. Users can use the application to review information and statistics about their previous runs. At the beginning of a run, users indicate the distance they want to run from their current location, and the application suggests a running route. Once a user accepts a suggested route, the application shares the suggested route with other compatible users in the area so that they can run together. Users are considered compatible if they are on each other's contact lists or if they typically run at similar speeds. A basic RunRoutr account is free, but it displays advertisements that are targeted to individual users based on data collected by the application. For example, if a user's running route begins or ends near a particular store, the application may display an advertisement for that store. Users have the ability to pay a monthly fee for a premium account, which removes advertisements from the application. Businesses have the ability to target advertisements to different groups of people who use RunRoutr. Which of the following groups is LEAST likely to receive targeted advertisements?

C Individuals who sign up for a premium account

ASCII is a character-encoding scheme that uses 7 bits to represent each character. The decimal (base 10) values 65 through 90 represent the capital letters A through Z, as shown in the table below. What ASCII character is represented by the binary (base 2) number 1001010 ? A H B I C J D K

C J

Which of the following best describes a direct benefit in using redundant routing on the Internet? A Redundancy enables messages to be transmitted with as few packets as possible. B Redundancy enables network devices to communicate with as few network connections as possible. C Redundancy often allows messages to be sent on the network even if some network devices or connections have failed. D Redundancy prevents network communications from being intercepted by unauthorized individuals.

C Redundancy often allows messages to be sent on the network even if some network devices or connections have failed.

In which of the following situations would it be most appropriate to choose lossy compression over lossless compression? A Storing digital photographs to be printed and displayed in a large format in an art gallery B Storing a formatted text document to be restored to its original version for a print publication C Storing music files on a smartphone in order to maximize the number of songs that can be stored D Storing a video file on an external device in order to preserve the highest possible video quality

C Storing music files on a smartphone in order to maximize the number of songs that can be stored

RunRoutr is a fitness tracking application for smartphones that creates suggested running routes so that users can run with each other. Upon downloading the application, each user creates a username, a personal profile, and a contact list of friends who also use the application. The application uses the smartphone's GPS unit to track a user's location, running speed, and distance traveled. Users can use the application to review information and statistics about their previous runs. At the beginning of a run, users indicate the distance they want to run from their current location, and the application suggests a running route. Once a user accepts a suggested route, the application shares the suggested route with other compatible users in the area so that they can run together. Users are considered compatible if they are on each other's contact lists or if they typically run at similar speeds. A basic RunRoutr account is free, but it displays advertisements that are targeted to individual users based on data collected by the application. For example, if a user's running route begins or ends near a particular store, the application may display an advertisement for that store. Users have the ability to pay a monthly fee for a premium account, which removes advertisements from the application. Adrianna uses RunRoutr to suggest a running route. All compatible users near Adrianna receive a notification that shows her running route. Which of the following data is not obtained using data collected from Adrianna's smartphone but necessary for RunRoutr to share Adrianna's running route?

C The current locations of other RunRoutr users

RunRoutr is a fitness tracking application for smartphones that creates suggested running routes so that users can run with each other. Upon downloading the application, each user creates a username, a personal profile, and a contact list of friends who also use the application. The application uses the smartphone's GPS unit to track a user's location, running speed, and distance traveled. Users can use the application to review information and statistics about their previous runs. At the beginning of a run, users indicate the distance they want to run from their current location, and the application suggests a running route. Once a user accepts a suggested route, the application shares the suggested route with other compatible users in the area so that they can run together. Users are considered compatible if they are on each other's contact lists or if they typically run at similar speeds. A basic RunRoutr account is free, but it displays advertisements that are targeted to individual users based on data collected by the application. For example, if a user's running route begins or ends near a particular store, the application may display an advertisement for that store. Users have the ability to pay a monthly fee for a premium account, which removes advertisements from the application. Which of the following is most likely to be a benefit to users of the application?

C Users of the application may see health benefits as a result of the application encouraging them to exercise with each other.

In a certain video game, players are awarded bonus points at the end of a level based on the value of the integer variable timer. The bonus points are awarded as follows. If timer is less than 30, then 500 bonus points are awarded. If timer is between 30 and 60 inclusive, then 1000 bonus points are awarded. If timer is greater than 60, then 1500 bonus points are awarded. Which of the following code segments assigns the correct number of bonus points to bonus for all possible values of timer ?

D In this code segment, if timer is greater than 60, bonus is assigned 1500 in the first IF block. If timer is between 30 and 60, inclusive, bonus is assigned 1000 in the second IF block. If timer is less than 30, bonus is assigned 500 in the third IF block. The correct number of bonus points is assigned to bonus for all possible values of timer.

A flowchart provides a way to visually represent an algorithm and uses the following building blocks. (BLOCK-EXPLANATION) Oval- The start or end of the algorithm Rectangle - One or more processing steps, such as a statement that assigns a value to a variable Diamond-A conditional or decision step, where execution proceeds to the side labeled true if the condition is true and to the side labeled false otherwise Parallelogram-Displays a message In the flowchart below, assume that j and k are assigned integer values. Based on the algorithm represented in the flowchart, what value is displayed if j has the initial value 3 and k has the initial value 4 ? A 7 B 9 C 10 D 12

D 12

A local router is configured to limit the bandwidth of guest users connecting to the Internet. Which of the following best explains the result of this configuration as compared to a configuration in which the router does not limit the bandwidth? A The amount of time it takes guest users to send and receive large files is likely to decrease. B The number of packets required for guest users to send and receive data is likely to decrease. C Guest users will be prevented from having fault-tolerant routing on the Internet. D Guest users will be restricted in the maximum amount of data that they can send and receive per second.

D Guest users will be restricted in the maximum amount of data that they can send and receive per second.

Which of the following is a primary reason for the use of open protocols on the Internet? A Open protocols allow devices to specify how data packets are to be routed on the Internet in advance. B Open protocols ensure that all data transmission on the Internet is kept secure. C Open protocols ensure that all Internet users are provided connections with equal bandwidth. D Open protocols provide a way to standardize data transmission between different devices.

D Open protocols provide a way to standardize data transmission between different devices.

Which of the following best explains the relationship between the Internet and the World Wide Web? A Both the Internet and the World Wide Web refer to the same interconnected network of devices. B The Internet is an interconnected network of data servers, and the World Wide Web is a network of user devices that communicates with the data servers. C The Internet is a local network of interconnected devices, and the World Wide Web is a global network that connects the local networks with each other. D The Internet is a network of interconnected networks, and the World Wide Web is a system of linked pages, programs, and files that is accessed via the Internet.

D The Internet is a network of interconnected networks, and the World Wide Web is a system of linked pages, programs, and files that is accessed via the Internet.

In the following procedure, the parameter n is an integer greater than 2. Which of the following best describes the value returned by the procedure? A The procedure returns nothing because it will not terminate. B The procedure returns the value of 2 * n. C The procedure returns the value of n * n. D The procedure returns the sum of the integers from 1 to n.

D The procedure returns the sum of the integers from 1 to n.

RunRoutr is a fitness tracking application for smartphones that creates suggested running routes so that users can run with each other. Upon downloading the application, each user creates a username, a personal profile, and a contact list of friends who also use the application. The application uses the smartphone's GPS unit to track a user's location, running speed, and distance traveled. Users can use the application to review information and statistics about their previous runs. At the beginning of a run, users indicate the distance they want to run from their current location, and the application suggests a running route. Once a user accepts a suggested route, the application shares the suggested route with other compatible users in the area so that they can run together. Users are considered compatible if they are on each other's contact lists or if they typically run at similar speeds. A basic RunRoutr account is free, but it displays advertisements that are targeted to individual users based on data collected by the application. For example, if a user's running route begins or ends near a particular store, the application may display an advertisement for that store. Users have the ability to pay a monthly fee for a premium account, which removes advertisements from the application. Which of the following data must be collected from a user's smartphone in order for RunRoutr to suggest a running route?

D The user's geographic position

A scientist wants to investigate several problems. In which of the following situations is using a simulation LEAST suitable for solving a problem? A When a scientific study requires performing a large number of trials that need to be conducted very quickly B When it is considered acceptable to make simplifying assumptions when modeling a real-world object or phenomenon C When performing an experiment that would be too costly or dangerous to conduct in the real world D When the solution to the problem requires real-world data inputs that are continually measured at regular intervals.

D When the solution to the problem requires real-world data inputs that are continually measured at regular intervals.

A flowchart provides a way to visually represent an algorithm and uses the following building blocks. (BLOCK-EXPLANATION) Oval- The start or end of the algorithm Rectangle - One or more processing steps, such as a statement that assigns a value to a variable Diamond-A conditional or decision step, where execution proceeds to the side labeled true if the condition is true and to the side labeled false otherwise Parallelogram-Displays a message In the flowchart below, assume that j and k are assigned integer values. Which of the following initial values of j and k will cause the algorithm represented in the flowchart to result in an infinite loop? A j = -5, k = 5 B j = 0, k = 5 C j = 5, k = 0 D j = 5, k = -5

D j = 5, k = -5

Consider the following procedures, which are used to control a device that draws lines on paper. Procedure Call-Explanation penDown()-Places the device's pen on the paper so that a line is drawn when the device moves penUp()-Lifts the device's pen off of the paper so that no line is drawn when the device moves goForward(x)-Moves the device forward x units turnRight(x)-Rotates the device in place x degrees clockwise (i.e., makes an in-place right turn) Consider the goal of using the device to produce the following drawing, where each line shown has a length of 10 units and the horizontal lines are 10 units apart. The device is positioned at the upper-left corner of a sheet of paper and is facing right. Which of the following code segments will produce the drawing shown?

D penDown() goForward(10) penUp() turnRight(90) goForward(10) turnRight(90) penDown() goForward(10)

The player controls in a particular video game are represented by numbers. The controls and their corresponding binary values are shown in the following table. ←01000 ↑01001 →01011 ↓01111 Jump11000 Run11001 Pause11011 Reset11111 The numeric values for the controls can also be represented in decimal (base 10). What control is represented by the decimal value 15 ? A ← B ↑ C → D ↓

D ↓

A video-streaming Web site uses 32-bit integers to count the number of times each video has been played. In anticipation of some videos being played more times than can be represented with 32 bits, the Web site is planning to change to 64-bit integers for the counter. Which of the following best describes the result of using 64-bit integers instead of 32-bit integers? A 2 times as many values can be represented. B 32 times as many values can be represented. C 232 times as many values can be represented. D 322 times as many values can be represented.

C 232 times as many values can be represented.

According to the domain name system (DNS), which of the following is a subdomain of the domain example.com? A about.example.com B example.co.uk C example.com.org D example.org

A about.example.com

The player controls in a particular video game are represented by numbers. The controls and their corresponding binary values are shown in the following table. ←01000 ↑01001 →01011 ↓01111 Jump11000 Run11001 Pause11011 Reset11111 The numeric values for the controls can also be represented in decimal (base 10). What is the decimal value for the jump control? A 3 B 12 C 24 D 48

C 24

In the following code segment, assume that the variable n has been initialized with an integer value. Which of the following is NOT a possible value displayed by the program? A "artichoke" B "broccoli" C "carrot" D "daikon"

C "carrot"

A code segment is intended to display the following output. up down down down up down down down Which of the following code segments can be used to display the intended output?

Repeat 2 Times Display "up" Repeat 3 times Display "down"

A sorted list of numbers contains 128 elements. Which of the following is closest to the maximum number of list elements that can be examined when performing a binary search for a value in the list? A 2 B 8 C 64 D 128

B 8