A shopkeeper earns a profit of ` 1 by selling one pen and incurs a loss of 40 paise per pencil while selling pencils of her old stock. (i) In a particular month she incurs a loss of ` 5. In this period, she sold 45 pens. How many pencils did she sell in this period? (ii) In the next month she earns neither profit nor loss. If she sold 70 pens, how many pencils did she sell?

SCERT Class 7 Telangana, Maths Chapter 1 Integers



Let's solve it by equations
let no. of pencils sold are x

so according to question (i)
0.4x -45*1 = 5   ( loss of 5 rs )
x = 50/0.4 
=> 125
She sold 125 pencils in this period

(ii) for the second part 
0.4x-70=0 (neither profit or loss)
x = 70/0.4
x value turns out to be 175

Hope it helps :)