Question

Type the correct answer in the box, Write your answer as a reduced fraction, using / for the fraction bar.

A six-sided fair die is rolled 4 times in a row. The probability of getting a 4 only on the last trials

Answer 1

P = 125/1296

Explanation:

P = Number of ways of getting only 4 at the last trial / Total number of ways

Number of ways of getting only 4 at the last trial = 5 * 5 * 5 * 1 = 125

(for the first three trials, all but 4 is permissible (6 - 1 = 5 ways), and

for the last trial, only 4 is permissible (1 way)).

Total number of ways = 6 * 6 * 6 * 6 = 1296

P = 125/1296