Q28. What is the difference between the age of C and D?

Question

Q28. What is the difference between the age of C and D?

1. A. 12 years
2. B. 10 years
3. C. 24 years
4. D. 37 years (Correct answer)
5. E. 38 years

Correct Answer

Option D — 37 years

Detailed Solution & Explanation

The correct answer is 37 years.

Key Points

• Puzzle setup: seven people born in 1947, 1959, 1964, 1973, 1978, 1988, 2001 (ages in 2025: 78, 66, 61, 52, 47, 37, 24).
• Applying the clues — C + F = D, G divisible by 6, A + G prime, A just older than F, A + B divisible by 5 — fixes the arrangement as B = 1947 (78), G = 1959 (66), D = 1964 (61), E = 1973 (52), A = 1978 (47), F = 1988 (37), C = 2001 (24).
• From the grid, C is 24 years old and D is 61 years old. The difference is:
• 61 − 24 = 37 years.
• once the full age grid is fixed, comparison questions become simple subtraction.
• The clue 'C + F = D' (24 + 37 = 61) is what locks C, F and D together, so verifying it also confirms this difference.

Exam Tip

• in a set of 5 questions on one puzzle, invest the time to build the complete grid once; every individual question (difference, oldest, specific age) is then answered in seconds.