Question

To gather data involving their classmates, 50 fourth graders each filled out a personal information survey sheet. In the category of pets, 22 students had a cat, 17 students had a dog, and 9 students had both a dog and a cat. If a student is randomly selected from this class, what is the probability the student will have a dog or a cat

Answer 1

0.60

Explanation:

In the category of pets

22 students had a cat = P(C)

17 students had a dog = P(D)

9 students had both a dog and a cat = P(C and D)

The formula to find the Probability of two events =

P(C or D) = P(C) + P(D) - P(C and D)

P(cat or dog) = P(cat) + P( dog) - P(cat and dog)

P(cat or dog) = 22/50 + 17/50 - 9/50

P(cat or dog) = 0.44 + 0.34 - 0.18

P(cat or dog) = 0.60

The probability the student will have a dog or a cat is 0.60