# A shopkeeper bought pens at a rate of 12 pens for 150 rs and sold them at rate of 10 pens for 130rs.The number of pens he should sell to earn a net profit of 20rs is?

## x(130/10) = x(150/12)+20

x = 40

## X is for what?

## Sdx

## To find the number of pens the shopkeeper should sell to earn a net profit of 20 rs, we can use the concept of cost price and selling price.

Let's first calculate the cost price of each pen:

The shopkeeper bought 12 pens for 150 rs.

So, the cost price of each pen = 150 rs / 12 pens = 12.5 rs/pen.

Next, let's calculate the selling price of each pen:

The shopkeeper sold 10 pens for 130 rs.

So, the selling price of each pen = 130 rs / 10 pens = 13 rs/pen.

Now, let's find out the profit per pen:

Profit per pen = Selling price per pen - Cost price per pen

= 13 rs/pen - 12.5 rs/pen

= 0.5 rs/pen

To earn a net profit of 20 rs, the shopkeeper needs to sell more pens to cover that profit. So, the number of pens he should sell can be calculated as:

Number of pens = Net profit / Profit per pen

= 20 rs / 0.5 rs/pen

= 40 pens

Therefore, the shopkeeper should sell 40 pens to earn a net profit of 20 rs.