Difficulty: Easy
Correct Answer: 10 years
Explanation:
Problem restatementRelate A, B, and C using the given age differences and total, then solve for B.
Given data
Concept/ApproachExpress everything in terms of C and substitute into the total.
Step-by-step calculation B = 2C; A = 2C + 2 (2C + 2) + 2C + C = 27 5C + 2 = 27 → 5C = 25 → C = 5 B = 2C = 10
VerificationA = 12, B = 10, C = 5; sum = 27 (consistent).
Common pitfalls
Final Answer10 years
Discussion & Comments