12. A shopkeeper earns a profit of 2 by selling one book and a loss of 50 paise per pen while selling

pens of his old stock. In a particular month he incurred a loss of? 10. In this period he sold 40

books. How many pens did he sell in this period?

pens of his old stock.

By Ariana

Answer:A shopkeeper earns a profit of Rs. 2 by selling one book and incurs a loss of 50 paise per pen while selling pencils of her old stock.

Profit per book Rs. 2

Loss per pen 50 paise,

(i) In a particular month she incurs a loss of Rs. 10.

The number of book sold 50.

Let the number of pen sold be x

Rs. 10 = Rs. 50(2) – Rs. 0.5(x)

=> 0.5x = 50-10

=> 0.5x = 40

=> x = (40)/(0.5)

=> x = 80.

Number of pencils sold=