A shopkeeper purchased a pen drive of marked price Rs. 1000 at successive discounts of 10% & 15% respectively. He spent Rs. 35 on packaging and sold it on Rs. 1000. Calculate the Gain percent
A No Gain
B. 25%
C. 30%
D. 35%

Options

A. D
B. C
C. A
D. B

Answer

To solve the problem step by step, we will follow these calculations:

### Step 1: Calculate the total discount on the marked price
The marked price of the pen drive is Rs. 1000. The shopkeeper receives successive discounts of 10% and 15%.

Using the formula for successive discounts:
\[ \text{Total Discount} = a + b - \left(\frac{a \times b}{100}\right) \]
where \(a = 10\%\) and \(b = 15\%\).

Substituting the values:
\[ \text{Total Discount} = 10 + 15 - \left(\frac{10 \times 15}{100}\right) = 25 - 1.5 = 23.5\% \]

### Step 2: Calculate the selling price after discount
Now, we need to calculate the discount amount on the marked price:
\[ \text{Discount Amount} = \frac{23.5}{100} \times 1000 = 235 \]

Now, we subtract the discount from the marked price to find the price after discount:
\[ \text{Price after discount} = 1000 - 235 = 765 \]

### Step 3: Calculate the cost price
The shopkeeper spends Rs. 35 on packaging. Therefore, the total cost price (CP) will be:
\[ \text{Cost Price} = \text{Price after discount} + \text{Packaging cost} = 765 + 35 = 800 \]

### Step 4: Calculate the profit
The selling price (SP) is Rs. 1000. Now, we can calculate the profit:
\[ \text{Profit} = \text{Selling Price} - \text{Cost Price} = 1000 - 800 = 200 \]

### Step 5: Calculate the gain percent
To find the gain percent, we use the formula:
\[ \text{Gain Percent} = \left(\frac{\text{Profit}}{\text{Cost Price}}\right) \times 100 \]
Substituting the values:
\[ \text{Gain Percent} = \left(\frac{200}{800}\right) \times 100 = 25\% \]

### Conclusion
The gain percent is **25%**. Therefore, the correct answer is **B. 25%**.

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