Question

The sum of 3 times the age of son and the age of his father is 110. If 3 times the age of his father is added to age of his son we get 170.Then what is the sum of their ages. Find their age

Answer 1

Son's age = x

Father's age = y

3x + y = 110 ....................(1)

x + 3y = 170 .....................(2)

1 + 2

4x + 4y = 280

So x + y  = 280/4 = 70   ..................(3)

Sum of their age = 70years

(2) - (1)

x + 3y - 3x - y = 60

-2x + 2y = 60

x - y  = -30  .............................(4)

(3) + (4)

x + y + x - y = 70 + -30

2x = 40

x = 20

Son's age = 20 years

x + y = 70

y = 70 - 20 = 50

Father's age = 50 years