Probability = (number of ways to succeed) / (total possible outcomes) .
The total possible results of rolling two dice is
(6 on the first cube) x (6 on the second one) = 36 possibilities.
How many are successful ? I need you to clarify something first. You said that the 'second die' shows an odd number. When a pair of dice is rolled, the problem usually doesn't distinguish between them. And in fact, you said that they're "tossed together" (like a spinach and arugula salad ?) so I would understand that they would lose their identity unless they were, say, painted different colors, and we wouldn't know which one is the second one.
Oh well, I'll just work it both ways:
First way: Two identical dice are tossed. The total is 5 and ONE cube shows an odd number.
How can that happen ?
1 ... 4 4 ... 1 3 ... 2 2 ... 3
Four possibilities. Probability = 4/36 = 1/9 = 11.1% .
======================================= Second way: A black and a white cube are tossed together. The total is 5 and the white cube shows an odd number.
How can that happen:
B ... W 4 .... 1 2 .... 3
Only two possibilities. Probability = 2/36 = 1/18 = 5.6% .
