Marks and percentage points: In a test of 400 marks, A scored 10 percentage points more than B, and B scored 5 percentage points more than C. If C scored 300 marks out of 400, find A’s marks.

Introduction / Context:
The phrase “scored x% more than” can be ambiguous. In many exam contexts, it is used to mean percentage points (i.e., absolute increase on the percent scale). We use that interpretation here, which produces an integer answer aligned with the options.

Given Data / Assumptions:

• Total marks = 400.
• C scored 300 ⇒ C% = 300/400 * 100% = 75%.
• B scored 5 percentage points more than C ⇒ B% = 80%.
• A scored 10 percentage points more than B ⇒ A% = 90%.

Concept / Approach:
Convert the given marks to percentage for C, adjust B and A by percentage points (not relative multipliers), then convert A’s percentage back to marks using the total of 400.

Step-by-Step Solution:

Verification / Alternative check:
If one (incorrectly) treats “% more” as relative increase, then B = 1.05*C and A = 1.10*B, giving 346.5, which is not among the options. The percentage-point reading resolves the ambiguity and matches a listed choice.

Why Other Options Are Wrong:

• 310, 325, 350: Do not correspond to 90% of 400.

Common Pitfalls:
Confusing percentage points with relative percent increases. Read carefully: exam comparisons often mean absolute percentage points for simplicity of scoring.

Final Answer: