Sonny is twice as old as Wale. Four years ago, he was four times as old as Wale. When will the sum of their ages be 66?
Explanation
Let Wale’s present age = x.
Then Sonny’s age = 2x
Four years ago, Wale = x – 4
Sonny = 4(x – 4) = 2x – 4
(4x – 16 = 2x – 4 implies 4x – 2x = -4 + 16)
(2x = 12 implies x = 6)
Sonny = 2x = 2(6) = 12 years
In z years’ time, the sum of their ages = 66
Wale = 6 + z
Sonny = 12 + z
(6 + z + 12 + z = 66 implies 18 + 2z = 66)
(2z = 66 – 18 = 48 implies z = 24)
Therefore, in 24 years time, the sum of their ages will be 66.