A shopkeeper who deals in books sells a book at a loss of 16 percent. If she had charged an additional Rs. 60 on the selling price, she would have made a profit of 14 percent instead. What is the cost price of the book in rupees?

Introduction / Context:
This is a classic profit and loss question involving two scenarios with the same cost price but different selling prices. In the first case there is a loss, and in the second case there is a profit after increasing the selling price by a fixed rupee amount. The task is to find the original cost price of the book using these two percentage conditions.

Given Data / Assumptions:

• In the first scenario, the book is sold at a loss of 16 percent.
• If the selling price is increased by Rs. 60, then there is a profit of 14 percent.
• The cost price of the book remains the same in both scenarios.
• We ignore any taxes or additional charges.
• We must determine the cost price in rupees.

Concept / Approach:
Let the cost price of the book be C. A loss of 16 percent means the selling price equals 84 percent of C. A profit of 14 percent means the selling price equals 114 percent of C. The second selling price is exactly Rs. 60 more than the first. Therefore, we can set up an equation connecting these two selling prices and C, and then solve for C using simple algebra.

Step-by-Step Solution:
Let cost price C be an unknown value in rupees.Selling price in the loss case is 84 percent of C, so S1 equals 0.84 * C.Selling price in the profit case is 114 percent of C, so S2 equals 1.14 * C.We are told that S2 is 60 rupees more than S1.Therefore, 1.14 * C equals 0.84 * C plus 60.Subtract 0.84 * C from both sides to get 0.30 * C equals 60.Hence C equals 60 divided by 0.30, which is 200 rupees.

Verification / Alternative check:
We can verify by computing both selling prices using C equals 200. With a 16 percent loss, S1 equals 200 * 0.84 which is 168 rupees. With a 14 percent profit, S2 equals 200 * 1.14 which is 228 rupees. The difference S2 minus S1 equals 228 minus 168 which is exactly 60 rupees, matching the problem statement. This confirms that C equals 200 rupees is consistent with both scenarios and the given increase in selling price.

Why Other Options Are Wrong:
If we take C as 185, 16 percent loss gives 155.4 and 14 percent profit gives 210.9, whose difference is not 60 rupees. For 154, the corresponding selling prices also do not differ by 60 rupees. For 177, the gap between loss selling price and profit selling price again does not match the required difference. Only 200 rupees produces selling prices that differ by exactly 60 rupees while matching both percentage conditions.

Common Pitfalls:
Some learners incorrectly assume that 16 percent and 14 percent sum directly to form a 30 percent gap in selling prices, which is not true because percentages are applied on the same cost price, not directly added on selling price. Others misinterpret which percentage corresponds to loss and which to profit, leading to a wrong equation. Working step by step and writing each selling price formula explicitly avoids these errors.

Final Answer:
The correct cost price of the book is Rs. 200.