What is the probability of rolling a 10 with three dices.

There are 6^3 = 216 possible permutations of throwing 3 dice. Of those possibilities, 27 add up to ten. They are:
1,3,6; 1,4,5; 1,5,4; 1,6,3; 2,2,6; 2,3,5; etc. up to ...6,2,2; 6,3,1
The probability of throwing 10 is therefore 27/216 = 1/8