Comparing parents’ ages via child’s milestone: A man was 32 years old when he had his first son. When the son turned 7, the wife was 35 years old. What is the age difference between the man and his wife?

Introduction / Context:
This problem uses ages at specific events to infer the parents’ relative ages. Align both parents’ ages at the same reference time (when the son is 7) to compute their difference.

Given Data / Assumptions:

• Father’s age when son born = 32.
• When son is 7, wife is 35.

Concept / Approach:
At the time the son is 7, the father is 32 + 7 = 39. Compare this to the wife’s 35 at the same instant to get the difference.

Step-by-Step Solution:
1) Father’s age when son is 7: 32 + 7 = 39.2) Wife’s age at that time: 35.3) Difference = |39 − 35| = 4 years.

Verification / Alternative check:
Because both ages are referenced to the same moment, the computed difference remains valid at all times.

Why Other Options Are Wrong:

• 7/3/5 years do not match the aligned-time comparison; 4 years is uniquely correct.

Common Pitfalls:
Comparing ages at different times or overlooking which parent’s age is specified at which event leads to errors.

Final Answer:
4 years