Question

A die is rolled five times and the number of fours that come up is tallied. Find the probability of getting the given result. Exactly 3 fours.

A. 0.161

B. 0.002

C. 0.116

D. 0.216

Answer 1

0.0321

Explanation:

This can be found by binomial probability distribution as the probability of success is constant. There are a given number of trials. the successive tosses are independent.

Here n= 5

The probability of getting a four in a roll of a die = 1/6

The probability of not getting a four in a roll of a die = 5/6

The probability of getting exactly three 4s in five throws is given by

5C3 (1/6)³ (5/6)² = 10 (0.0046) (0.694)= 0.0321