A shopkeeper sells two articles at a ₹840 each. He earns a 20% profit on the first article and incurs a 20% loss on the second article. Determine the percentage of net profit or loss he incurs.

Correct option is C

Given:

Selling Price of each article =₹840

Profit made on one =20%

Loss made on another=20%

Formula Used:

Profit = Selling Price - Cost Price

Loss = Cost Price - Selling Price

Loss Percentage =$$\frac{Loss}{Cost\ Price}\times 100$$​

Profit Percentage =$$\frac{Profit}{Cost\ Price}\times 100$$​

Solution:

Let the Cost Price of device sold on profit be x

Then Selling Price of device will be x + 20% of x = x + 0.2x = 1.2x

But Selling Price = 840

1.2x = 840

​$$x= \frac{840}{1.2} = ₹700$$​ 

Let the Cost Price of device sold at loss be y

Then Selling Price = y - 20% of y = 0.80y

0.80y = 840

​$$y= \frac{840}{0.8} = ₹1050$$​ 

Total cost price of both devices = 700+1050 = ₹1750

Total selling price =$$840 \times 2$$​ = ₹1680

Loss = 1750 - 1680 = ₹70

Loss percentage = $$\frac{70}{1750} \times 100 = 4\%$$​​