Compound Probability

If two events A and B are disjoint, meaning they CANNOT happen at the same time, what is P(A or B)?

•  $P(A)-P(B)$  

•  $P(A)\cdot P(B)$  
  

•  $P(A)+P(B)$  

•  $\frac{P(A)}{P(B)}$  

If two events A and B are NOT disjoint, meaning they CAN happen at the same time, what is P(A or B)?

•  $P(A)-P(B)+P\left(AandB\right)$  

•  $P(A)\cdot P(B)-P\left(AandB\right)$  
  

•  $P(A)+P(B)-P\left(AandB\right)$  

•  $\frac{P(A)}{P(B)}+P\left(AandB\right)$  

A spinner with 5 colors is spun and a 6-sided die is rolled. How many outcomes are in the sample space?

• 2

• 11

• 24

• 30

A teacher wanted to know the probability of selecting a student at random that either plays sports OR has blond hair. The teacher counted ALL of the students that play sports and then ALL of the students with blond hair, and added the totals together. What did the teacher do wrong?

• He didn't count the students with dark hair.

• He undercounted the students who play sports and have blond hair.

• He overcounted the students who play sports and have blond hair.

• He didn't ask the students what sports they play.

What is P(K or 5)?

• $\frac{4}{52}=\frac{1}{13}$

• $\frac{8}{52}=\frac{2}{13}$

• $\frac{16}{52}=\frac{4}{13}$

• $\frac{9}{52}$

What is P(heart or 4)?

•  $\frac{13}{52}=\frac{1}{4}$ 

•  $\frac{30}{52}=\frac{15}{26}$ 

• $\frac{16}{52}=\frac{4}{13}$

•  $\frac{17}{52}$ 

What is P(black or 7)?

•  $\frac{26}{52}=\frac{1}{2}$ 

•  $\frac{30}{52}=\frac{15}{26}$ 

•  $\frac{28}{52}=\frac{7}{13}$ 

•  $\frac{32}{52}=\frac{8}{13}$ 

What is P(red or even)?

• $\frac{4}{8}=\frac{1}{2}$

• $\frac{5}{8}$

• $\frac{6}{8}=\frac{3}{4}$

• $\frac{7}{8}$

What is P(red or odd)?

• $\frac{4}{8}=\frac{1}{2}$

• $\frac{5}{8}$

• $\frac{6}{8}=\frac{3}{4}$

• $\frac{7}{8}$

What is P(blue or odd)?

• $\frac{4}{8}=\frac{1}{2}$

• $\frac{5}{8}$

• $\frac{6}{8}=\frac{3}{4}$

• $\frac{7}{8}$