Question

This Venn diagram shows the pizza topping preferences for 9 students. Let event A = The student likes pepperoni. Let event B = The student likes olives. What is P(A or B)?​

Answer 1

Answer:

$P(A\ or\ B)=\frac{7}{9}$

Step-by-step explanation:

We need to use the formula to calculate the probability of (A or B) where  

A=Probability a student likes pepperoni

B=Probability a student likes olive

A and B =Probability a student likes both toppings in a pizza

A or B =Probability a student likes pepperoni or olive (and maybe both), a non-exclusive or

The formula is

$P(A\ or\ B)=P(A)+P(B)-P(A\ and\ B)$

Since 6 students like pepperoni out of 9:

$P(A) = \frac{6}{9}$

Since 4 students like olive out of 9:

$P(B) = \frac{4}{9}$

Since 3 students like both toppings out of 9

$P(A\ and\ B) = \frac{3}{9}$

Then we have

$P(A\ or\ B)=\frac{6}{9}+\frac{4}{9}-\frac{3}{9}$

$P(A\ or\ B)=\frac{7}{9}$