The present age of a man is 4 years more than twice the present age of his son. After 6 years, the sum of their ages will be 58 y…
Mathematics ·Previously asked in RRB NTPC 2026
View the full solved paper: RRB NTPC UG 2026 (7 May, Shift 1)
Question
The present age of a man is 4 years more than twice the present age of his son. After 6 years, the sum of their ages will be 58 years. What is the present age of the son?
- A. 10 years
- B. 11 years
- C. 14 years (Correct answer)
- D. 9 years
Correct Answer
Option C — 14 years
Detailed Solution & Explanation
The correct answer is 14 years.
Shortcut Trick
- Test the options against the second condition — with four choices this is often faster than forming equations.
- If the son is 14, the man is $2(14) + 4 = 32$. After 6 years they are 20 and 38, summing to 58 ✓.
Alternate Method
- Let the son's present age be s. Then the man's age is $2s + 4$.
- After 6 years: son $= s + 6$, man $= 2s + 10$.
- Given their sum is 58:
- $(s + 6) + (2s + 10) = 58$
- $3s + 16 = 58$
- $3s = 42 \Rightarrow s = \textbf{14}$
- The man is therefore 32 now, and in 6 years they will be 20 and 38.
Additional Information
- The reliable habit in age problems: add the same number of years to *every* person. Here two people gain 6 years each, so the combined sum rises by 12, not 6 — the single most common error in this question type.
- Working backwards, the sum today is $58 - 12 = 46$, which also gives $3s + 4 = 46 \Rightarrow s = 14$.
- The difference between two people's ages never changes, so any statement about their difference applies at every point in time.
Topics covered: Ages Mathematics