Q.A man is 3 times as old as his son. in ten yrs time, the sum of their ages will be 76. How old was the man when his son was born?
Method below...
(x+10) + (3x+10) = 76
4x + 20 = 76
4x = 76 - 20
4x = 56 , x = 56 / 4 =14
When his son was born, the man was 2x = 2 x 14 28yrs old.
Why would x = 14 be multiplied by 2?
Note that the son's age now = x = 14
And the father's age is 3x = 3(14) = 42
So......14 years ago....the father was 42 - 14 = 28 years old