In a family, the father took 1/4 of the cake and he had 3 times as much as others had. The total number of family members is?

Let there be N members, other than father .
Father's share = 1/4, other's share = 3/4.
Each of other's share = 3/4N
∵ 3 x 3/4N = 1/4
∴ N = 9
Hence, the total number of members = N + 1 = 10