Probability Problem set-ups
3/10 x 5/9
A bag contains 5 green candles, 2 yellow candles, and 3 red candles. What is the probability of picking a red candle and then a green candle from the bag without replacement?
5/10 x 4/9 x 3/8
A bag contains 5 green marbles, 3 yellow marbles, and 2 red marbles. What is the probability of picking three green marbles from the bag without replacement?
2 x 7 x 4
A bicycle manufacturer makes five- and ten- speed bikes in seven different colors and four different frame sizes. How may different bicycles does the manufacturer make?
2/1000 x 75,000
A quality control inspector at a light bulb factory finds 2 defective bulbs in a batch of 1000 light bulbs. If the plant manufactures 75,000 light bulbs in one day, predict how many will be defective.
2 x 9
A shoe manufacturer makes brown and black shoes in nine different sizes. How many different shoes does the manufacturer make?
5/10 x 200 or 5/10 = n/200
A spinner has 10 equal divisions numbered 1 to 10. Predict the number of times that an even number will occur in 200 spins.
5/10 = n/200 OR 5/10 x 200
A spinner has 10 equal divisions number 1 to 10. Predict the number of times that an even number will occur in 200 spins.
4/8 = n/120 OR 4/8 x 120
A spinner has 8 equal divisions, number 1 to 8. How many times will an even number occur in 120 spins?
18/32 x 1200 = 675
Before a school vote on a mascot for a community river project, a sample of students surveyed gave the otter 18 votes, the osprey 8 votes, and the beaver 6 votes. Based on these results, predict the number of votes for otter if 1200 students vote.
14 C 4
Find the number of different 4-person teams that can be made from 14 people.
25 P 4
From a class of 25 students, how many different ways can 4 students be selected to serve in a mock trial as the judge, defending attorney, prosecuting attorney, and the defendant?
5 x 3 x 4
How many different combinations of sandwich, side, and beverage are possible: Sandwiches: Hot Dog, Hamburger, Veggie burger, Bratwurst, Grilled Chicken Sides: Chips, Apple, Pasta Salad Beverages: Bottled Water, Soda, Juice, Milk
21 P 4
How many ways can a teacher choose the first, second, third, and fourth students to give a presentation from a class of 21?
1/26 x 1/25 x 1/24
If Justine's initials are JMD, what is the probability that she will draw her initials from a box containing the letters of the alphabet? There is no replacement of letters after each is drawn.
150/300 = n/400 OR 150/300 x 400
Last week the cafeteria sold 80 sandwiches, 150 salads, and 70 mini-pizzas. If the order for next week includes 400 lunches, how many salads are likely to be sold?
4/8 x 3/7
Lee has a bag that contains 4 red chips and 4 blue chips. What is the probability of drawing two red chips in two draws if the first chip is not replaced into the bag?
8 C 3
Lisa's club is selling cookies. She wants to buy 3 different boxes. If there are 8 kinds of cookies, how many choices does she have?
5/15 x 4/14
Margaret has a bag containing 5 red chips, 5 blue chips, and 5 yellow chips. What is the probability of drawing two blue chips in two draws without replacement?
5/10 x 4/9
Margaret has a bag containing 5 red marbles and 5 blue marbles. What is the probability of drawing two red marbles in two draws without replacement?
7 C 3
Shane wants to attend 3 concerts. He has a choice of 7. How many concert combinations are there?
4 C 2
Shara wants to adopt 2 of the 4 kittens at the pet shelter. How many different combinations of kittens does she have to choose from?
12/36 x 10/35
Sid has a bag of 12 red, 14 brown, and 10 blue marbles. He chooses one, shoots it, and chooses another. What is the probability that his first selection is a red marble, and then a blue marble?
5/60 x 180 or 5/60=n/180
Since the last order, a office supply store has sold 30 cases of black pens, 25 cases of blue pens, and 5 cases of red pens. The next order will be for 180 cases of pens. How many cases of red pens are likely to be sold in the next order?
15/150 = n/500 OR 15/150 x 500
The school store sells 15 red, 107 blue, and 28 purple pens. If they purchase 500 more pens, how many red pens should they order?
10/40 x 13/39
There are 13 math students, 10 science students, and 17 English students in a group. If only one prize is allowed per person, what is the probability that the moderator will award a science student a prize and then award another prize to a math student?