1. A stationer buys pens at 5 for 28 and sellsthem at a profit of 25%.

1.	1. A stationer buys pens at 5 for 28 and sellsthem at a profit of 25%. How much should acustomer pay; if he buys(1) only one pen ?(ii) three pens?
Answer» For Stationery : C.P. of 5 pens = Rs. 28 C.P. of 1 PEN = 28/5 Rs. = Rs. 5.60 Profit = 25% ∴ S.P. of 1 Pen = (100 + Profit%)/100 × C.P. of 1 pen = ((100 + 25)/100) × Rs. 5.60 = Rs. 125/100 × 5.60 = Rs. (125 × 5.6)/100 = Rs. 5 × 1.4 = Rs. 7 S.P. of 3 Pens = 3 × 7 = Rs. 21 ∴ Customer pays for (i) Only one pen = Rs. 7 (ii) Three pens = Rs. 21

1. A stationer buys pens at 5 for 28 and sellsthem at a profit of 25%. How much should acustomer pay; if he buys(1) only one pen ?(ii) three pens?

Answer»

For Stationery :

C.P. of 5 pens = Rs. 28

C.P. of 1 PEN = 28/5 Rs. = Rs. 5.60

Profit = 25%

∴ S.P. of 1 Pen = (100 + Profit%)/100 × C.P. of 1 pen

= ((100 + 25)/100) × Rs. 5.60 = Rs. 125/100 × 5.60

= Rs. (125 × 5.6)/100 = Rs. 5 × 1.4 = Rs. 7

S.P. of 3 Pens = 3 × 7 = Rs. 21

∴ Customer pays for

(i) Only one pen = Rs. 7

(ii) Three pens = Rs. 21