Question

A father's age in 3 years will be twice the son's age 4 years ago. The sum of their ages is now 106. How old is the father now

Answer 1

Using only one variable:

`x` - father's age

`106-x` - son's age

`x+3=2(106-x-4)\\x+3=212-2x-8\\3x=201\\x=67`

The father is 67 years old.

Answer 2

the father is currently 67 years old.

Explanation:

F + 3 = 2S - 8

F = 2S - 8 - 3

F = 2S - 11

(2S - 11) + S = 106

3S - 11 = 106

3S = 106 + 11

3S = 117

S = 117 / 3

S = 39

F + 39 = 106

F = 106 - 39

F = 67