Profit and Loss — A person buys 100 pens with a 10% purchase discount; the net amount paid is ₹ 600. Selling expenses are 15% of the net cost price. What total selling price is required for 100 pens to earn an overall profit of 25%?

Introduction / Context:
When selling expenses are given as a percentage of cost, the true effective cost equals purchase cost plus selling expenses. The desired profit should be computed on this effective cost to find the total selling price needed.

Given Data / Assumptions:

• Net purchase outlay for 100 pens = ₹ 600 (after 10% discount).
• Selling expenses = 15% of net cost (i.e., 0.15 * 600).
• Target overall profit = 25% on effective cost.

Concept / Approach:
Effective cost = Net purchase + Selling expenses. Required total SP = Effective cost * 1.25. This gives the minimum total revenue to achieve the stated profit over all cost components.

Step-by-Step Solution:

Verification / Alternative check:
Profit = 862.50 − 690 = 172.50 ⇒ 172.50/690 * 100 = 25%.

Why Other Options Are Wrong:
802.50 and 811.25 fall short of a 25% margin on effective cost; 875 overshoots slightly; 840 does not match 25% exactly.

Common Pitfalls:
Computing 25% profit on net purchase only (ignoring selling expenses), which would understate the true required selling price.

Final Answer:
₹ 862.50