Under a discount scheme, after allowing a discount of 20%, there is still a gain of 10%. The marked price is what percentage more than the cost price?

Correct option is B

Given:
A discount of 20%, there is still a gain of 10%.
Formula Used:
​$$\frac{\text{MP}}{\text{CP}} = \frac{100 + \text{Profit\%}}{100 - \text{Discount\%}}$$​​
Solution:
​$$\frac{\text{MP}}{\text{CP}} = \frac{100 + \text{Profit\%}}{100 - \text{Discount\%}} \\\frac{\text{MP}}{\text{CP}} = \frac{110}{80} \\\frac{\text{MP}}{\text{CP}} = \frac{11}{8}$$​​
According to the question:
11 - 8 = 3
Marked Up by = $$\frac38$$​ × 100 = 37.5%

Alternate Solution: