Multiple choice

Two years ago a man was six times as old as his own son. In 18 years he will be twice as old as his son. What is the present age of the son?

  1. 7

  2. 9

  3. 11

  4. 13

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let the present ages be: son = x years, man = y years. Two years ago: (y-2) = 6(x-2). In 18 years: (y+18) = 2(x+18). From first equation: y-2 = 6x-12, so y = 6x-10. Substitute into second: 6x-10+18 = 2x+36, so 6x+8 = 2x+36, 4x = 28, x = 7. The son's present age is 7 years. Option A is correct.