Chapter 12 Study Guide

Probability

100

What is probability?

Probability is a number that shows how likely an event will occur

200

What are 3 ways (number forms) you can show probability?

Fraction, decimal, percent

300

How can you find the decimal form of the fraction 3/8?

(Divide the numerator by the denominator) 

3 ÷ 8 = .375

400

Easter Egg #4:

'til

500

What is the formula for the probability of an event?

p (event) = number of favorable outcomes / number of total possible outcomes

Scenario #1: M&Ms

100

There are 20 M&Ms. 5 are red, 7 are blue, 8 are green. What is the probability (fraction) of pulling red?

A.) 5/20

B.) 7/20

C.) 1/4

C.) 1/4

200

There are 15 M&Ms. 2 are brown, 6 are green, 3 are yellow, 4 are orange. What is the probability (percent) of pulling yellow?

A.) 10%

B.) 20%

C.) 30%

B.) 20%

because 3/15 = 1/5

1/5 = 20% (scale factor is 20)

300

Easter Egg #2: 

more

400

There are 30 M&Ms. 15 are blue, 8 are brown, 3 are red, 4 are yellow. What is the probability (decimal rounded) of pulling brown?

A.) .25

B.) .26

C.) .27

C.) .27 

because 8/30 = .26666667 so you have to round up which gives you .27

500

There are 10 M&Ms. 4 are red, 3 are yellow, 2 are green, 1 is orange. What is the probability (percent) of pulling red?

A.) 40%

B.) 30%

C.) 20%

A. 40%

Scenario #2: Game Board

100

What is the probability of selecting a black tile?

A.) 2/8

B.) 3/8

C.) 6/16

B.) 3/8 

because you have to reduce 6/16 = 3/8

200

What is the probability of selecting a white tile? 

A.) 0.625

B.) 0.630

C.) 0.635

A.) 0.625

(because 10/16 = 5/8 which is .625 when you divide 5 by 8)

300

What is the probability of selecting a black tile?

A.) 10%

B.) 50%

C.) 75%

B.) 50%

400

What is the probability of selecting a white tile?

A.) .35

B.) .40

C.) .45

C.) .45

because 9/20 = 45/100 (scale factor is 5) so 45/100 = .45

500

Easter Egg #1:

One 

Scenario #3: Dice

100

You have one 6-sided die, what is the probability that the number is less than 5?

A.) 4/6

B.) 3/6

C.) 2/3

C.) 2/3 

because 4/6 is reduced to 2/3

200

Easter Egg #3: 

month

300

You have two 6-sided die, what is the probability that the number is a product of 20?

A.) 3/36

B.) 1/18

C.) 1/5

B.) 1/18 

because 2/36 is reduced to 1/18

400

You have two 6-sided die, what is the probability of rolling a sum of 6?

A.) 43%

B.) 4/30

C.) .14

C.) .14

because there are 5 possibilities (1:5, 5:1, 2:4, 4:2, 3:3). 5/36 = .138... which is rounded to .14

500

Easter Egg #5:

summer!