When a bicycle manufacturer reduced the selling price of a bicycle by 50%, the number of bicycles sold radically increased by 700%. Initially. the manufacturer was getting a profit of 140%. What is the new profit percentage?

Correct option is D

Given:

Selling price reduced by 50%.

Number of bicycles sold increases by 700%.

Initial profit is 140%. 

Formula Used: 

Profit % = $$\frac{SP - CP}{CP}\times 100$$​​

Solution: 

Let the Cost price of bicycle = C 

Initial selling price: $$S = C + \left(\frac{140}{100} \times C\right) = 2.4C$$  

New selling price after 50% reduction:$$S_{\text{new}} = \frac{S}{2} =\frac{2.4C}{2}= 1.2C$$​ 

$$\text{New Profit} = S_{\text{new}} - C = 1.2C - C = 0.2C$$​​

$$\text{New Profit Percentage} = \frac{0.2C}{C} \times 100 = 20\%$$​

Thus new profit percentage is 20%.