Question

Bill's father is three times Bill's age. Three years ago, Bill's father was four times Bill's age.

By forming two equations, find Bill's age now.

Answer 1

12 and 36

Explanation:

Call the age of both Bill and his father is a and b, respectively

we have:

b=3a

b-3=4(a-3) ->b=4a-12 -> 3a=4a-12 ->a =12 -> b=36