Question

If cost price of 25 books is equal to selling price of 20 books, then calculate the gain or loss percent.

• A. 80
• B. 20
• C. 25
• D. 50

Answer 1

Answer:

C. 25

1. Set up the Ratio

According to the question:
$25 \times \text{CP} = 20 \times \text{SP}$

Now, rearrange the terms to find the ratio of SP to CP:
$\frac{\text{SP}}{\text{CP}} = \frac{25}{20} = \frac{5}{4}$

2. Identify Gain or Loss

• Cost Price (CP) = $4$ units

• Selling Price (SP) = $5$ units

• Since the selling price is higher than the cost price, it is a Gain.

3. Calculate the Percentage

$\text{Gain} = 5 - 4 = 1 \text{ unit}$

$\text{Gain \%} = \left( \frac{\text{Gain}}{\text{CP}} \right) \times 100$

$\text{Gain \%} = \left( \frac{1}{4} \right) \times 100 = \mathbf{25\%}$