Person A is 20 years older than person B and also six times as old as B. Find their present ages (A, B) in years.

Introduction / Context:
Two simultaneous linear relations (difference and multiple) uniquely determine two unknown ages. Solve by substitution or elimination.

Given Data / Assumptions:

• A = B + 20
• A = 6B

Concept / Approach:
Equate the two expressions for A to get a single equation in B, then recover A.

Step-by-Step Solution:

Verification / Alternative check:
Check: A − B = 24 − 4 = 20 and A = 6 × 4 = 24. Both hold.

Why Other Options Are Wrong:
42, 7 or 30, 5 do not satisfy both the +20 and ×6 conditions together.

Common Pitfalls:
Mixing the add and multiply constraints or solving for A first and forgetting to back-substitute correctly.

Final Answer:
24, 4.