A fair eight-sided die is rolled six times. A success is getting a 6, 7 and 8. Find the probability of getting three successes.

Answer 1

prob(success) in a single toss = 3/8

prob(3 successes in 6 tries)
= C(6,3) (3/8)^3 (5/8)^3
= 20(27/512)(125/512)
= 67500/262144
= 16875/65536
= appr .257