If the probability that 20 kids or fewer kids in a group of 25 like pizza is 43%, what is the probability that at least 21 kids in the group like pizza?

Options: A. 25% B. 43% C. 57% D. 21%

57%

Step-by-step explanation:

Given

Number of kids = 25

Probability that 20 or fewer kids like Pizza = 43%

Required

Probability that at least 21 kids in the same group like pizza

In probability, summation of opposite probabilities is always equal to 1;

The opposite of 20 or fewer kids is 21 or more kids

21 or more kids means at least 21 kids

Since we mentioned that summation of opposite probability is always equal to 1

This can be represented as follows;

Probability of 20 or fewer kids + Probability of 21 or more kids = 1

Given that Probability that 20 or fewer kids like Pizza is 43%;

By substitution, we have

43% + Probability of 21 or more kids = 1

Collect like terms

Probability of 21 or more kids = 1 - 43%

Convert percentage to decimal

Probability of 21 or more kids = 1 - 0.43

Probability of 21 or more kids = 0.57

Convert decimal to percentage

Probability of 21 or more kids = 57%

Hence, the probability that at least 21 kids in the group like Pizza is 57%