Question

A father’s age is 7 years more than the 3 times of son’s age. If father’s age           is 31 years, find son’s age.

Answer 1

Let the the father's age be x and the sons age be y.
x = 3y + 7
31 = 3y + 7
31 - 7 = 3y
24/3 = y
8
The son's age  = 8

Answer 2

Father's age = x and sons age = y.
x = 3y + 7
31 = 3y + 7
31 - 7 = 3y
24/3 = y
8