Problems on Ages Practice Test 1 with solutions

Let the present ages of father and his son be x and (45 – x) years respectively; then
(x – 5) (45 – x – 5) = 4 (45 – x – 5)
⇒ x – 5 = 4
∴ x = 9
Now, son's age = 45 – x = 45 – 9 = 36 years