Question

Three dice are thrown simultaneously. What is the probability of obtaining a total of 17 or 18 

(A) 1/9 

(B) 1/72 

(C) 1/54 

(D) None of these 

Answer 1

Answer is (C) 1/54

Three dices can be thrown in 6 x 6 x 6 = 216 ways.

A total 17 can be obtained as (5,6,6) , (6,5,6), (6,6,5). A total 18 can be obtained as (6,6,6) . Hence, 

the required probability = 4/216 = 1/54