A Shop keeper earns a profit of RS 1 by selling one pen & incurs a loss of 40 paise per pencil by selling pencils of her old stock. 

1.In a particular months she incurs a loss of Rs 5. In this period she sold 45 penns. How many pencils did she sell in this period?

2.In the next month she earns profit nor loss. If she sold 70 pens, how many pencils did she sell?

he earns profit of Rs. 1by selling one pen and

and looses 40 paise / pencil by selling one pencil.

1.

loss in the particular month = Rs. 5.

the number of pen sold = 45 pens.

profit = 45*1 = 45/-

therefore total loss that month = 45+5 = 50/-

loss by selling one pencil = paise 40 = Rs. 0.40 

therefore number of pencil sold that month =

thus she sold 125 pencils that month.

2.

since she sold 70 pens.

profit by selling 70 pens = 70*1 = 70/-

since she made neither profit  nor loss.

thus total loss = total profit = 70/-

number of pencil sold that month =

thus in the next month she sold 175 pencils.

hope this helps you.

cheers!!