​A shopkeeper sells pulses at Rs.100 per kg that he purchased for Rs80 per kg. While selling. he cheats and gives 800 g instead of 1 kg. What is his actual profit?

Correct option is B

Given:

Cost price (CP) per kg = Rs. 80

Selling price (SP) per kg = Rs. 100

Instead of selling 1 kg, the shopkeeper gives only 800 grams (i.e., 0.8 kg). 

Formula Used:

​$$\text{Profit Percentage} = \left( \frac{\text{Profit}}{\text{Cost Price}} \right) \times 100$$ 

Solution: 

Cost Price of 800 gm = 0.8 × 80 = 64 Rs.

The shopkeeper sells 800 g for Rs. 100 (even though he claims it’s 1 kg).

Selling Price of 800 g = 100 Rs.

Profit = Selling Price − Cost Price = 100 − 64 = 36 Rs

Substituting the values in above formula 

​$$\text{Profit Percentage} = \left( \frac{36}{64} \right) \times 100 = 56.25\%$$ 

Thus profit percentage is 56.25%.