Refresher Probability

Refresher Compound Probability

More than 1 event ("AND")

"AND" IS MULTIPLY!!!!!

P(win AND win) so MULTIPLY!

 $\frac{1}{6}\cdot\frac{1}{6}=\frac{1}{36}$  
There is a 1 out of 36 chance of winning 2 times in a row

Refresher Probability "OR" so ADD!

 $P\left(red\ or\ blue\right)=\frac{1}{8}+\frac{3}{8}=\frac{4}{8}or\ \frac{1}{2}$ 

red: 7

blue: 4,5,6 

Refresher Two-way Table

• P(male football) = 20/100

• P(basketball or baseball) = 67/100

• P(female or baseball) = (88-23)/100 = 65/100

• P(male given football) = 20/33

Multiple Choice

What is the probability of the spinner landing on an even number?

• 1/8

• 1/2

• 2/8

• 1/3

Multiple Choice

What is the probability of landing on a number greater than or equal to 4?

• 5/8
• 4/8
• 1/2
• 2/3

Multiple Choice

You roll a six sided die. What is the probability of rolling an even number three times in a row?

• 3/100

• 1/2

• 1/6

• 1/8

Multiple Choice

A coin and a number cube with the numbers 1 through 6 are tossed. What is the probability of the coin showing tails and the number cube showing the number 3?

• 1/12

• 1/4

• 1/8

• 1/2

Multiple Choice

Which of the following shows how to determine P(shaded number or number less than five)?

• 4/8 + 4/8 - 2/8

• 4/9 + 2/8 - 4/8

• 4/8 + 6/8 + 2/8

• 2/8 + 4/8 - 4/8

Multiple Choice

The make-up of employees at a police station is shown in the table above:

What is the probability that a randomly selected employee is a chief?

• 1/100

• 2/100

• 1/33

• 1/67

Multiple Choice

The make-up of employees at a police station is shown in the table above:

What is the probability that a randomly selected employee is male and a sergeant?

• 8/13

• 8/33

• 8/67

• 8/100

Multiple Choice

The two-way table above gives information about the grades for the semester in Mrs. Hardcase’s English class.

What is the probability a randomly selected student got an A or B for the semester?

• 15/100

• 20/100

• 35/100

• 65/100

Multiple Choice

Which of the following shows how to determine P(packers or male)?

• 75/150 + 90/150 - 50/150
• 75/150 + 35/150 - 25/150
• 50/150 + 40/150 + 25/150
• 90/150 + 50/150 - 75/150

Multiple Choice

The two-way table above gives information about the grades for the semester in Mrs. Hardcase’s English class.

Given that the grade is an A, what is the probability of the student being female?

• 8/20

• 12/20

• 8/44

• 12/56