Question
There are two urns. Urn A has 3 distinct red balls and urn B has 9 distinct blue balls. From each urn two balls are taken out at random and then transferred to the other. The number of ways in which this can be done is
-
3
-
36
-
66
-
108
Solution
D.
108
The number of ways in which two balls from urn A and two balls from urn B can be selected
= 3C2 x 9C2 = 3x 36 = 108
