Question

you roll two standard number cubes. What is the probability that the sum is odd, given that one of the number cubes shows a 4?

Answer 1

if one is already rolled as a 4, then there are only 6 other total combinations to get.so what are sums to get an odd number?
4+1=5
4+3=7
4+5=9
so you have a 1/2 chance of getting an odd number, given that one of the dice is already a 4.