Ages (linear relation with total): A is two years older than B, and B is twice as old as C. If A + B + C = 27, find B's present age.

Introduction / Context:
Linear relations among three ages combined with a total allow quick variable substitution. This problem is a straightforward arithmetic exercise intended to reinforce systematic setup and solution.

Given Data / Assumptions:

• A = B + 2.
• B = 2C.
• A + B + C = 27.

Concept / Approach:
Eliminate A and B in favor of C (or any single variable). Solve for C from the sum, then compute B directly from B = 2C.

Step-by-Step Solution:

Verification / Alternative check:
Sum 12 + 10 + 5 = 27 (✓); relations A = B + 2 and B = 2C both hold (✓).

Why Other Options Are Wrong:
They correspond to incorrect solutions for C that do not satisfy the total or the given relations.

Common Pitfalls:
Adding instead of substituting, or mixing which person is twice as old as whom, which flips the relation.

Final Answer:
10