Jack has two dice, one has six equally probable sides, labeled 1, 2, 3, 4, 5, 6, and the other has seven equally probable sides, labeled 1, 2, 3, 4, 5, 6, 7. If Jack rolls both dice what is the probability that both of the numbers will be odd? A. 3/14 B. 2/7 C. 1/3 D. 1/2 E. 12/21
(B) For the first die there are 6 possible numbers, for the second die there are 7 possible numbers. When both are rolled together there are (6)(7) = 42 possible combinations. On the first die there are 3 odd numbers and on the second die there are 4 odd numbers. There are (3)(4) = 12 possible combinations where both numbers are odd. The probability that both numbers will be odd is 12/42 = 2/7. 
How would I solve this if the question was: If Jack rolls both dice what is the probability that AT LEAST ONE of the numbers will be odd?
