A student's originally awarded marks were later reduced by 40% of the original award during re-evaluation, leaving a new score of 96. How many marks did the student lose due to re-evaluation?

Introduction / Context:
The reduction is a percentage of the original marks, not of the revised marks. We first recover the original award, then compute the absolute loss.

Given Data / Assumptions:

• Let original marks = M.
• Reduction = 40% of M.
• New score after reduction = 96.

Concept / Approach:
New score = M − 0.40M = 0.60M. Solve 0.60M = 96 for M, then subtract to find the loss amount (which is 0.40M).

Step-by-Step Solution:

Verification / Alternative check:
Check: Original 160, minus 64 equals 96, matching the revised score.

Why Other Options Are Wrong:
56, 58, 60, 68 arise from computing 40% on the wrong base or arithmetic slips.

Common Pitfalls:
Treating ”reduced by 40% of original marks” as ”new score is 40% of original,” which would be incorrect here. The remainder is 60% of original.

Final Answer:
64