Time-sequence / ranking within pass list: In a class of 45 students, among those who passed, Anmol is 11th from the top and 15th from the bottom. How many students failed?

Introduction / Context:When a person’s rank from the top and from the bottom within a subset are known, the size of that subset is top_rank + bottom_rank - 1. Subtract from class size to get failures.

Given Data / Assumptions:

• Total class = 45.
• Anmol among passers: 11th from top, 15th from bottom.

Concept / Approach:Let P be number of passed. Then P = 11 + 15 - 1 = 25. Failures = 45 - 25.

Step-by-Step Solution:

Verification / Alternative check:Counting includes the individual once, hence the subtraction of 1.

Why Other Options Are Wrong:Other counts assume incorrect subset sizing or ignore the -1 rule.

Common Pitfalls:Adding ranks without subtracting 1, double-counting the person.

Final Answer:20