Pair of fair dice is rolled. what is the probability of each of the following? (round your answers to three decimal places.)

(a) the sum of the numbers shown uppermost is less than 4

(b) at least one 6 is cast

we are given with two dice and that we are asked in the problem to find the probability of the following:
a. sum at least 4b. sum at least 6
THe sample space of this problem is 
{11, 12, 13, 14, 15, 16, 21,22, 23,24,25,26,31,32,33,34,35,36,41,42,43,44,45,46,51,52,53,54,55,56,61,62,63,64,65,66} a total of 36.a. 33/36 = 11/12b.11/36