Calculating the Purchase Price of a Watch: A Comprehensive Guide

Calculating the Purchase Price of a Watch: A Comprehensive Guide

In this article, we will explore how to calculate the purchase price of a watch given certain selling price conditions. This involves understanding the relationship between the marked price, cost price, and the applied discounts.

Introduction

When dealing with price and profit adjustments, it's crucial to understand how much the shopkeeper initially paid for the item and how much they aim to profit from it. This article will provide a step-by-step process to determine the purchase price of a watch based on its marked price and the selling price after a discount.

Problem Definition

A watch was sold at its marked price with a gain of 20, but after allowing a 5 discount, the gain would have been Rs. 140 only. We need to find out at what price the shopkeeper purchased the watch.

Step-by-Step Solution

To solve this problem, let's define the following variables:

CP (Cost Price): The price at which the shopkeeper purchased the watch. MP (Marked Price): The price at which the watch is marked for sale.

Step 1: Establish Equations Based on the Problem

First, we need to set up the equations based on the given information:

When the watch is sold at its marked price with a gain of 20, the selling price (SP) is: When a 5 discount is allowed on the marked price, the selling price is: After the discount, the selling price results in a gain of Rs. 140.

The equations can be derived as:

Selling price at marked price (SP) with a gain of 20:

SP MP 1.20CP

Selling price after a 5 discount (SPdiscounted):

SPdiscounted MP - 0.05MP 0.95MP

Selling price with a gain of Rs. 140:

SPdiscounted CP 140

Step 2: Substitute and Solve

By substituting the first equation into the second, we get:

0.95MP CP 140

Revising MP as 1.20CP:

0.95(1.20CP) CP 140

Simplifying the equation:

1.14CP CP 140

Step 3: Rearrange and Solve for CP

Subtract CP from both sides:

1.14CP - CP 140

0.14CP 140

Solving for CP:

CP 140 / 0.14 1000

Conclusion

The shopkeeper purchased the watch for Rs. 1000.

Explanation of the Solution

The solution involves using the relationship between the marked price, cost price, and the applied discount. By solving the equations, we can determine the cost price and ensure the shopkeeper's profit margin is maintained appropriately.

Summary of Key Concepts

Marked Price (MP): The price at which the item is marked for sale. Cost Price (CP): The price at which the shopkeeper buys the item. Profit or Gain: The difference between the selling price and the cost price. Discount: The reduction in the marked price offered to the customer.

Related Keywords

cost price markup discount gain purchase price