We roll five standard dice (sides numbered 1 to 6) and write down the sum of the top three i.e. of the 3 highest values.
What is the probability to get 15 ?
(In reply to
analytical attempt at it by Vishal Gupta)
From your solution:
6,6,3,1,1 and 6,6,3,2,2 have 5!/2!2! = 30 ways each
6,6,3,3,1 and 6,6,3,3,2 have 5!/2!2! = 30 ways each
You forgot to count these twice. You had 60 + 30 + 30 + 10 = 130. It should be 60 + 30*2 + 30*2 + 10 = 190. Otherwise, nicely done.

Posted by hoodat
on 20101116 16:21:44 