John buys a laptop for Rs 1,75,000 and sells it to Mark at a loss of 20%. Mark then sells it to Kevin at a profit of 25%. Kevin later returns the laptop to Mark but can recover only Rs 4.50 for every Rs 5 he had paid. What is the amount of loss incurred by Kevin?

Introduction / Context:
This is a chain transaction problem involving successive buying and selling between three people: John, Mark and Kevin. Each transaction has its own profit or loss condition. Finally, Kevin returns the laptop and recovers only a fraction of what he paid. We must track Kevin's outflow and inflow of money to determine his net loss. Problems of this type test careful step-by-step tracking of multiple profit and loss operations.

Given Data / Assumptions:

• John's cost price = Rs 1,75,000.
• John sells to Mark at a loss of 20%.
• Mark sells to Kevin at a profit of 25%.
• When Kevin returns the laptop, he receives only Rs 4.50 for every Rs 5 he originally paid.
• We must find Kevin's monetary loss.

Concept / Approach:
We first compute the price at which John sells to Mark using the 20% loss. Then we compute the price at which Mark sells to Kevin using the 25% profit on Mark's cost. That price is Kevin's purchase price. When Kevin returns the laptop, he gets 4.5/5 of what he paid. His loss is the difference between what he paid and what he recovered. Each step uses profit or loss percentage formula SP = CP * (1 ± rate).

Step-by-Step Solution:
Step 1: John's cost price = Rs 1,75,000.Step 2: John sells to Mark at 20% loss, so Mark's cost price = 1,75,000 * 0.8 = Rs 1,40,000.Step 3: Mark sells to Kevin at 25% profit, so Kevin's buying price = 1,40,000 * 1.25 = Rs 1,75,000.Step 4: When Kevin returns the laptop, he recovers only Rs 4.50 for every Rs 5 he paid, i.e., 4.5/5 = 0.9 of his purchase price.Step 5: Amount Kevin recovers = 0.9 * 1,75,000 = Rs 1,57,500.Step 6: Kevin's loss = amount paid - amount recovered = 1,75,000 - 1,57,500 = Rs 17,500.

Verification / Alternative check:
Notice that Kevin originally pays Rs 1,75,000 and effectively gets back 90% of this amount, since 4.5/5 equals 0.9. Losing 10% of 1,75,000 gives 0.1 * 1,75,000 = 17,500, which matches the detailed calculation above. The intermediate Mark transaction is important for understanding how Kevin's purchase price arises, but once it is known, Kevin's loss is simply 10% of that amount.

Why Other Options Are Wrong:
Rs 16,500, Rs 14,200 and Rs 15,520 are values that might appear if one misapplies the profit and loss percentages at different stages, or if one mistakenly calculates 10% on the wrong base such as John's cost price or Mark's cost price. Only Rs 17,500 correctly represents 10% of Kevin's actual purchase price of Rs 1,75,000, given the 4.5 to 5 repayment ratio.

Common Pitfalls:
A frequent mistake is to think that Mark's profit or John's loss somehow affects Kevin's eventual percentage loss directly. In reality, Kevin's loss depends only on what he paid and what he recovered. Another pitfall is to confuse the 4.5 to 5 ratio with a 5% loss instead of a 10% loss. Always convert the ratio to a decimal and compare it with 1 to find the correct percentage change.

Final Answer:
Kevin incurs a loss of Rs. 17,500 on the laptop transaction.