If two integers, a and b, are randomly chosen with replacement from the set of integers ranging from 1 to 80, inclusive, what is the probability that the product a*b is divisible by 2?

Answer Choices

Correct answer marked below

3/4

Correct

1/4

1/2

9/16

7/8

See the full step-by-step explanation

You can see the correct answer above. Sign in for free to unlock the complete worked solution.

Track your performance and improve

Get detailed analytics, unlock full explanations, and move up difficulty tiers as you practice.

Start for free Sign in

Explanation

Preview

Official Explanation

Official

When selecting integers a and b from the set of 1 to 80, we need to determine when the product a*b is even. This occurs if at least one of the integers is even. To find the probability that a*b is odd, we consider the case where both a and b are odd. There are 40 odd numbers in the range from 1 to 80. Therefore, the total number of…

Read the full explanation

Create free account Sign in

Comments

PraveenNov 16, 2024

Great

What this question tests

What it tests

Your ability to compute probabilities of single and compound events, including 'at least one' questions.

Common trap

Forgetting to use the complement for 'at least one', or treating dependent events as independent.