If the cost price of 15 shirts is equal to the selling price of 10 shirts, then what will be the gain or loss percent?

Correct option is A

Given:

Let:
- The Cost Price (CP) of 1 shirt be C
- The Selling Price (SP) of 1 shirt be S
According to the question:
​$$15 \times C = 10 \times S$$​​

Formula Used:

To find the gain or loss percent, we can use:
- If there's a gain, Gain Percent =  $$\frac{\text{SP} - \text{CP}}{\text{CP}} \times 100$$​​
- If there's a loss, Loss Percent = $$\frac{\text{CP} - \text{SP}}{\text{CP}} \times 100$$​​

Solution:

​$$15 \times C = 10 \times S\\which \ implies:\\\frac{S}{C} = \frac{15}{10} = 1.5$$​​

This means that the Selling Price is 1.5 times the Cost Price, indicating a gain.

The Gain Percent:
Gain Percent =  $$\left( \frac{S - C}{C} \right) \times 100$$​​
Since S = 1.5C ,
Gain Percent =  $$\left( \frac{1.5C - C}{C} \right) \times 100$$​​

Gain Percent =  $$\left( \frac{0.5C}{C} \right) \times 100 = 50\%$$​​

The gain percent is 50%.