Ages (nested family offsets): Your age is 10 years less than half your mother's age. Your mother is 5 years younger than your father, who is 45. Find your present age.

Introduction / Context:
Composing two offsets (mother relative to father, you relative to mother) gives a simple linear chain. Work from the known father's age downward to obtain the required value cleanly.

Given Data / Assumptions:
Father = 45 ⇒ Mother = 45 − 5 = 40 ⇒ You = (1/2)*40 − 10.

Concept / Approach:
Substitute step by step; avoid doing everything at once to reduce mistakes in multi-clause statements.

Step-by-Step Solution:

Verification / Alternative check:
Half of mother's age is 20; you are 10 less than that, hence 10 (✓).

Why Other Options Are Wrong:
They result from halving the wrong person's age or subtracting 10 in the wrong place.

Common Pitfalls:
Confusing “5 years younger than” with “5 times younger,” or halving after subtracting 10.

Final Answer:
10 years