Question

If a fair die is rolled 5 times, what is the probability, rounded to the nearest

thousandth,
of getting at most 2 threes?

Answer 1

0.965 to the nearest thousand.

Explanation:

This is a binomial probability distribution.

Prob(getting no 3's) = (5/6)^5 = 0.4019

Prob(getting 1 * 3 ) = 5C1(1/6)(5/6)^4 = 0.4019

Prob (getting 2 3's ) = 5C2(1/6)^2(5/6)^3 = 0.1608

So required probability = 2 * 0.4019 + 0.1608

= 0.9646