By selling 175 pineapples, a fruit seller earns a profit that is exactly equal to the selling price of 50 pineapples. What is the percentage gain made by the seller on each pineapple?

Introduction / Context:

This problem involves profit percentage and requires you to interpret a verbal condition relating total profit to the selling price of a certain number of items. Such questions are common in profit and loss topics in aptitude exams and help you understand how to translate real-world statements into algebraic equations.

Given Data / Assumptions:

• The seller sells 175 pineapples.
• Total profit earned is equal to the selling price of 50 pineapples.
• Cost price per pineapple is assumed to be the same for all pineapples.
• Selling price per pineapple is also the same for all pineapples.

Concept / Approach:

The key idea is to use variables for cost price and selling price per pineapple and then use the relationship between total profit and selling price. If cost price per pineapple is C and selling price per pineapple is S, then total profit on 175 pineapples is (S − C) * 175. The question states that this profit equals the selling price of 50 pineapples, that is 50 * S. Solving this equation gives the ratio S/C, and from that we can compute profit percentage.

Step-by-Step Solution:

Verification / Alternative check:

Assume a convenient cost price to verify, for example C = Rs 5. Then S = (7/5) * 5 = Rs 7. Profit per pineapple is Rs 2. Profit on 175 pineapples is 175 * 2 = Rs 350. Selling price of 50 pineapples is 50 * 7 = Rs 350. Both match perfectly, confirming that a 40% profit is correct.

Why Other Options Are Wrong:

• 32%: This would correspond to a smaller ratio between S and C that does not satisfy the given equality between profit and selling price of 50 pineapples.
• 28% and 30%: Both represent lower profit margins, and if used to compute S / C, they will not make the profit on 175 items equal to the selling price of 50 items.
• 35%: Also does not satisfy the specific algebraic relationship derived from the condition in the question.

Common Pitfalls:

Many students confuse total profit with profit percentage and may incorrectly equate 175 to 50 or directly attempt a shortcut without forming an equation. Another error is to assume cost price is 1 and mis-handle fractions. The safest approach is always to introduce variables, write down the profit expression clearly, and then solve systematically for S/C.

Final Answer:

The seller's gain percentage is 40%.