Question #c5b12

1 Answer
Mar 9, 2016

#2/7#

Explanation:

the first friend has #7# books to choose from, #3# of which are mystery books. Therefore there are #3# out of #7# chances that the first friend will choose a mystery book. Probability of #3/7#

Once this happens, the second friend is choosing from #6# books, #2# of which are mystery books and #4# of which are romance books. The second friend therefore has #4# out of #6# chances of picking a romance book - probability of #4/6 = 2/3#.

The probability of both these events happening is the product of the two probabilities, so #3/7*2/3 = 2/7#