Question

a businessman allows a discount of 10% on the list price how much above the cost price he must mark to make profit of 20%​

Answer 1

He is already in the loss of 10% as he gives a discount now to make profit of 20% he should sell the product 30% above the cost price to make profit of 30%

Answer 2

The marked price will be more than the cost price by 33%.

Step-by-step explanation:

Let the cost price is x and the marked price is y.

To make 20% profit the selling price will be $x(1 + \frac{20}{100} )= 1.2x$

Now, if the businessman allows a discount of 10% on the list price, then the selling price will be $y(1 - \frac{10}{100}) =0.9y$

As both the selling prices calculated above are the same, so,  

1.2x = 0.9y, ⇒ y = 1.33x  

Therefore, the percentage by which the marked price will be more than cost price is

$\frac{y - x}{x} \times 100= \frac{1.33x - x}{x} \times 100 = 33$% (Answer)