Question 114

A man bought 9 pens for a rupee. How many pens should he sell for a rupee to gain 50%?

Solution

Cost price of 1 pen = Rs. $$\frac{1}{9}$$

Let he sells $$x$$ pen, => Selling price of 1 pen = Rs. $$\frac{1}{x}$$

=> Profit % = $$\frac{(S.P.-C.P.)}{C.P.}\times100=50\%$$

=> $$[(\frac{1}{x}-\frac{1}{9})\div(\frac{1}{9})]\times100=50$$

=> $$\frac{9-x}{x}=\frac{1}{2}$$

=> $$18-2x=x$$

=> $$x+2x=3x=18$$

=> $$x=\frac{18}{3}=6$$

$$\therefore$$ The man should sell 6 pens to gain 50%

=> Ans - (B)

Create a FREE account and get: