20 pens costing Rs.60 are sold at 5 pens for Rs. 25. What is the profit per cent?

Correct option is D

Formula Used:

$$\text{Profit \%} = \left( \frac{\text{S.P} - \text{C.P}}{\text{C.P}} \right) \times 100$$​

Solution:

Cost of 20 pens = Rs. 60

=> Cost of 1 pen = 60/20 = 3

SP of 5 pens = Rs. 25

=> SP of 1 pen = 25/5 = 5

Now, Profit = 5 – 3 = 2

Profit % = 2/3 × 100 = $$66\frac23\%$$​​