Question

Elliot wrote a computer program that randomly generates a number from 2 to 10. If he runs the program twice, what is the probability that the number generated both times is a prime number?

Answer 1

16/81

Explanation:

Answer 2

16/81

Explanation:

The program generates numbers from 2 to 10; this is 9 total possible values (2, 3, 4, 5, 6, 7, 8, 9, 10).

Out of these, there are 4 prime numbers: 2, 3, 5, 7

The probability of choosing a prime number once is 4/9.

The probability of choosing a prime number the second time is 4/9.

Together, the total probability is 4/9(4/9) = 16/81.