Question

Two dice are tossed. What is the probability that their sum will be 3, given that exactly one face shows 2?

Answer 1

if one face shows a 2, there are the following possibilities
\[(1,2),(2,2),(3,2),(4,2),(5,2),(6,2),(2,1),(2,3),(2,4),(2,5),(2,6)\]

Answer 2

how many of those give you a total of 3?

Answer 3

ooh, i didn't read carefully , it said "EXACTLY face shows a 2"\[(1,2),(3,2),(4,2),(5,2),(6,2),(2,1),(2,3),(2,4),(2,5),(2,6)\]
gotta get rid of the double twos

Answer 4

Would it be 1/36? or do I have to divide 2/36?

Answer 5

let the first dice be the one that shows 2, without loss of generality
the second dice can show any number except 2. it can show 1,3,4,5,or 6
of these possibilities, only the first one will result in a sum of 3. thus, the chance is 1/5