Question

Coach Johnson is 10 years older than Tim. When Tim started football 3 years ago, Coach Johnson was twice his age. How old is Tim now?

Answer 1

Let Tim's age now = x years
Then coach Johnson's age now = (x + 10) years

Three years ago,
Tim's age was = (x - 3) years
Coach Johnson's age was = (x + 10 - 3) years = (x + 7) years

ATQ, x+ 7 = 2(x - 3)
x + 7 = 2x - 6
7 + 6 = 2x - x
13 = x

So Tim is now 13 years old.