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प्रश्न
A man is four times as old as his son. After 20 years, he will be twice as old as his son at that time. Find their present ages.
उत्तर
Let the present age of the son = x years
Present age of the father = 4x years
After 20 years,
Son’s age will be (x + 20) years
and Father’s age will be (4x + 20) years
According to the condition,
4x + 20 = 2 (x + 20)
4x + 20 = 2x + 40
4x – 2x = 40 – 20
2x = 20
⇒ x = 10
∴ Present age of the son = 10 years and Present age of the father = 4×10 years = 40 years
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