Different-subject ranks – Sairam is 23rd from the top in Mathematics and 27th from the bottom in Physics. How many students are there in the class?

Introduction / Context:
The formula N = top + bottom − 1 works only for the same arrangement. If the two ranks come from different subjects (i.e., different orderings), you cannot combine them to get class size.

Given Data / Assumptions:

• Maths rank: 23rd from top.
• Physics rank: 27th from bottom.
• No linkage is given between the two subject-wise orderings.

Concept / Approach:
Because orderings differ across subjects, “23rd from top” in Maths does not correspond to a fixed bottom-rank complement in Physics. The two values cannot be summed.

Step-by-Step Solution:
We lack a single, consistent lineup relating both ranks. Therefore, N is undetermined.

Verification / Alternative check:
Construct counterexamples with the same class size but different Physics ordering; you can realize many possible N values consistent with the stated ranks.

Why Other Options Are Wrong:
Any fixed number presumes one ordering, which is not provided.

Common Pitfalls:
Blindly applying N = L + R − 1 across different subjects.

Final Answer:
Data inadequate