A shopkeeper bought 60 pencils at a rate of 4 for Rs. 5 and another 60 pencils at a rate of 2 for Rs. 3. He mixed all the pencils and sold them at a rate of 3 for Rs. 4. Find his gain or loss percentage.

Answer: Option B

Cost of one pencil = Rs. $$\frac{5}{4}$$
Cost of 60 pencil = $$\frac{5}{4}$$ × 60 = Rs. 75
Cost of single second-type pencil = Rs. $$\frac{3}{2}$$
Cost of 60 second-type pencil = $$\frac{3}{2}$$ × 60 = Rs. 90
Total cost price = 75 + 90 = Rs. 165
Selling price of one pencil = Rs. $$\frac{4}{3}$$
Total selling price = $$\frac{4}{3}$$ × 120 = Rs. 160
Total loss = 165 - 160 = Rs. 5
Loss % = $$=\frac{5}{165}\times 100=3\frac{1}{33}\%$$
∴ The loss incurred is $$3\frac{1}{33}\%$$