The cost price and selling price of an article are in the ratio of 3 : 7. If the selling price is Rs. 700, then find the cost price

Options

A. Rs. 500
B. Rs. 400
C. Rs. 300
D. Rs. 800

Answer

To solve the problem, we need to find the cost price of an article when the cost price and selling price are in the ratio of 3:7, and the selling price is given as Rs. 700.

### Step-by-Step Solution:

1. **Understand the Ratio**:
The cost price (CP) and selling price (SP) are in the ratio of 3:7. This means that for every 3 parts of cost price, there are 7 parts of selling price.

2. **Assign Variables**:
Let the cost price be represented as \( 3x \) and the selling price as \( 7x \), where \( x \) is a common multiplier.

3. **Set Up the Equation**:
We know the selling price is Rs. 700. Therefore, we can write the equation:
\[ 7x = 700 \]

4. **Solve for \( x \)**:
To find \( x \), divide both sides of the equation by 7:
\[ x = \frac{700}{7} = 100 \]

5. **Calculate the Cost Price**:
Now that we have \( x \), we can find the cost price:
\[ CP = 3x = 3 \times 100 = 300 \]

6. **Conclusion**:
The cost price of the article is Rs. 300.

### Final Answer:
The cost price is Rs. 300.

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