Five years ago, a father’s age was 5 times his son’s age. Today, the father’s age is 3 times his son’s age. What is the father’s present age?

Introduction: Age problems translate to linear equations with time shifts. We express both ages at two moments and solve for the present ages that satisfy both relationships.

Given Data / Assumptions:

• Let current ages be F (father) and S (son).
• Five years ago: F − 5 = 5(S − 5).
• Now: F = 3S.

Concept / Approach: Substitute F = 3S into the first equation, then solve for S. Finally obtain F and select the correct option.

Step-by-Step Solution:

Verification / Alternative check: Five years ago: father 25, son 5 → indeed 25 = 5*5; now 30 = 3*10, both conditions satisfied.

Why Other Options Are Wrong: 33, 35, 45 do not satisfy both time-based relationships simultaneously.

Common Pitfalls: Misapplying the time shift to only one person or mixing the 5-year difference incorrectly.

Final Answer: 30 years