Question

A pet store has two tanks of tropical fish. The first tank contains 7 blue fish and 3 yellow fish and the second tank contains 10 blue fish and 8 yellow fish. If Keisha randomly purchases a fish from each tank, what is the probability that both fish will be blue? A. 1/70 B. 17/180 C. 7/18 D. 17/28

Answer 1

In the first tank we have 7 blue fish and 3 yellow fish, so total number of fishes in tank 1 = 10

The probability of picking a blue fish in tank 1 = number of blue fishes/ total number of fishes = 7/10

The second tank has 10 blue fish and 8 yellow fish, so the total number of fishes in tank 2 = 18

The probability of picking a blue fish in tank 2 = number of blue fishes/ total number of fishes = 10/18

The probability that both fish will be blue = 7/10 * 10/18 = 70/180 = 7/18 (Option C)