A father tells his son: “I was as old as you are now at the time of your birth.” If the father is 38 now, how old was the son five years ago?

Difficulty: Medium

Correct Answer: 14 years

Explanation:

Problem restatementAt the son's birth, the father's age equaled the son's current age. Use this to find the son's present age, then subtract five years.

Given data

  • Father's current age F = 38.
  • Let son's current age = S.
  • At son's birth (S years ago), father's age = F − S.
  • Statement: F − S = S.

Concept/ApproachSet up F − S = S ⇒ 2S = F and solve directly.

Step-by-Step calculation2S = 38 ⇒ S = 19Son's age five years ago = 19 − 5 = 14

Verification/AlternativeAt birth: father's age = 38 − 19 = 19, equal to the son's present age (19). Consistent.

Common pitfallsInterpreting the statement as “at birth father's age equals son's age at birth” (which is zero).

Final Answer14 years

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