Loss percentage from ratio data: If the cost price (CP) and selling price (SP) of an article are in the ratio 5 : 3, compute the percentage loss.

Introduction / Context:
Ratios of CP:SP immediately reveal the percentage gain or loss. If CP > SP, it is a loss; if SP > CP, a profit. The percentage is measured on the cost price base.

Given Data / Assumptions:

• CP : SP = 5 : 3.

Concept / Approach:
Loss% = (CP − SP) / CP * 100. Substitute the ratio values directly as proportional numbers.

Step-by-Step Solution:
Loss parts = 5 − 3 = 2Loss% = 2 / 5 * 100 = 40%

Verification / Alternative check:
Assume CP = ₹ 5 and SP = ₹ 3. Loss = ₹ 2 which is 40% of ₹ 5, consistent.

Why Other Options Are Wrong:

• 35% / 45% / 26%: not supported by the 5:3 ratio when computed against CP.

Common Pitfalls:

• Using SP as the base (would give 66.66...%). Always use CP as the base for profit/loss percentage.

Final Answer:
40%