Question

Five years ago, the father's age was five times the son's age. In ten years' time, the father will be twice as old as his son. Find their present ages.​

Answer 1

Let f be the father's age and s be the son's age.

f - 5 = 5(s - 5)------>f - 5 = 5s - 25

f + 10 = 2(s + 10)--->f + 10 = 2s + 20

f - 5s = -20

f - 2s = 10

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3s = 30, so s = 10 and f = 30.

The son's age is 10, and the father's age is 30.