Probability?

Question

I have to find the probability of this:
"Two six-sided number cubes are rolled. What is the probability of getting a 3 on exactly one of the number cubes?" I know the answer is 5/18. I know ur supposed to put the number of
favorable outcomes/number of possiable outcomes
but I don't get how you find the number of favorable outcomes.

PLEASE HELP!!!!

Any faster ways?!?!

Answer 1

If you make a 6 by 6 grid of the outcomes, with 1 through 6 as outcomes along the top and along the left side, you'll have a grid of squares with 36 total possible outcomes. If you check off the outcomes where a 3 is showing on one dice but not the other, you should be showing 10 different check marks (the square where both dice show a 3 won't count). 10/36 reduces to 5/18.

Answer 2

all possible outcomes is 6^2=36
favorable outcomes=first cube only has 3 cases+second cube only has 3 cases= 5 + 5

So the probabilty is 10/36=5/18

note there are 6 outcomes that make one cube getting 3
3,1 3,2 3,3 3,4 3,5 3,6
but since we are intrested in the case one exactly one cube has 3 we must drop the case 3,3