Question

The age of father is 4 time the age of his son. Five years ago father was 9 times as old as his son was at that time the age of son is?

Answer 1

Answer:

age of father be x

age of son be y

x = 4y

(x - 5) = 9(y - 5)

x - 5 = 9y - 45

x -14y + 45 = 0

4y - 14y + 45 = 0

-10y = -45

y = 4.5 years

x = 4(4.5) = 18

Answer 2

Let age = x

Let father age = y

Thus, y=4x

and, y−5=7(x−5) or y=7x−30

Thus, 4x=7x−30

3x=30 or x=10

Hence, y = 40 years

Thus, age of father is 40 years.