A standard six-sided die is rolled twice. What is the probability that the product of the rolls is 3 or 12?
36 possible rolls
to produce product 3 , possible rolls are 1,3 and 3,1
for 12 6,2 2,6 3,4 4,3
6 rolls out of 36 = 1/6 probability
Note that it is clear that the answer is 1/61/6: Whatever we got on the first roll, the probability of matching it is 1/61/6. But if you want to use the sample space of 3636, the "favourables" are (1,1)(1,1), (2,2)(2,2), …….Monkey.cool