A’s salary is 30% more than B’s. By what percentage is B’s salary less than A’s?

Introduction / Context:
Percent “more than” and percent “less than” are asymmetric. If A is 30% more than B, then the percent by which B is less than A is not 30%; it must be computed using A as the base.

Given Data / Assumptions:

• A = 1.30B.
• We seek (A − B)/A * 100%.

Concept / Approach:
Express A in terms of B, compute the difference relative to A. This yields a fraction independent of B that can be converted to a mixed percent.

Step-by-Step Solution:

Verification / Alternative check:
Let B = ₹100 ⇒ A = ₹130. B is ₹30 less than A; 30/130 = 3/13 ≈ 23.08%.

Why Other Options Are Wrong:
30% and 33 1/3% misapply symmetry; 25% is a round guess; 20% is unrelated.

Common Pitfalls:
Assuming “more than” and “less than” percentages are identical in magnitude. Always use the correct base for the comparison.

Final Answer:
23 1/13