CodeHS Unit 8 Quiz

Consider the following numbers: The decimal value 10(base 10) The binary value 1001(base 2) Hexadecimal value C(base 16) Which of the following lists the numbers in order from least to greatest?

1001(base 2), 10(base 10), C(base 16)

What is the decimal value of 1101(base 2)?

13(base 10)

How many different digits are used in the Hexadecimal number system?

16

How many different values can be represented using 4 bits?

16 different values

An online store uses 8-bit binary values to identify each unique item for sale. The store plans to increase number of items it sells and is considering changing to 9-bit binary values. Which of the following best describes the result of using 9-bit values instead of 8-bit values?

2 times as many items can be uniquely identified

Suppose the ESPN website uses 8-bit unsigned integers to store how many points a team has scored in an NBA game. For example: 0000 0010 represents 2 points 0000 1000 represents 8 points What is the highest possible score the ESPN website could display?

255(base 10)

A news website uses 32-bit integers to count the number of times an article has been viewed. The website is becoming more popular, and expects some of the articles to exceed the number of views that can be represented with 32 bits. In anticipation of this, the website is planning to change to 64-bit integers for the view counter. Which of the following best describes the result of using 64-bit integers instead of 32-bit integers?

2^32 times as many values can be represented

A computer program uses 3 bits to represent integers. When the program adds the decimal (base 10) numbers 6 and 2, the result is 0. Which of the following is the best explanation for this result?

An overflow error occurred.

Which number system is used to store information digitally in a computer?

Binary(base 2)

Which ASCII character is represented by the decimal (base 10) number 72?

H

Suppose we have the following function that modifies a pixel and returns the result: var RED = 0; var GREEN = 1; var BLUE = 2; function filter(pixel) { pixel[RED] = 255 - pixel[RED]; pixel[GREEN] = 255 - pixel[GREEN]; pixel[BLUE] = 255 - pixel[BLUE]; return pixel; } Which of the following best describes the result of applying this filter to every pixel in the image?

The image will be inverted, bright pixels will become dark and dark pixels will become bright.

A student is transferring photos from her camera to her computer. The student notices that the saved photos on her computer are lower quality than the original raw photo on her camera. Which of the following could be a possible explanation for the difference in image quality?

The saved image files were compressed with a lossy compressing technique.

Which of the following is a true statement about data compression?

There are trade-odds involved in choosing a compression technique for storing and transmitting data.

The RGB encoding scheme encodes a color using 24 bit sequences. The first 8 bits encode the amount of red in the color, the next 8 bits encode the amount of green in the color, and the last 8 bits encode the amount of blue in the color. Which of the following is a true statement about the color encoded by this binary sequence: 1110 1001 0111 1100 0000 1111

This color is mostly red.

ASCII is a character encoding scheme that uses a numeric value to represent each character. For example, the uppercase letter 'G' is represented by the binary (base 2) value 0100 0111, which is equivalent to the decimal (base 10) value 71. ASCII characters can also be represented by hexadecimal (base 16) numbers. According to the ASCII character encoding, which of the following characters is represented by the hexadecimal (base 16) number 6E(base 16)?

n