Question

In a family, the father took 1/5 of the cake and he had 4 times as much as others had, then the family members are________. A. 16 B. 17 C. 18 D. None of these

Answer 1

There is one cake
It is divided among x family members, so each gets:
1/x
The father took 1/5 which is 4 times greater than each one's piece. So:
1/5 = 4(1/x)
1/5 = 4/x
x = 20
There are 20 family members so the answer is none of these