If a chair is sold at a discount of 20%, then there is a profit of 20%. If the chair is sold at a discount of 30%, then what will be the profit?

Let's assume the MRP of the chair is 150y.

If a chair is sold at a discount of 20%.

Selling price of the chair = 150y of (100-20)%

= 150y of 80%

= $$150y\times\frac{80}{100}$$

= 120y

then there is a profit of 20%.

Cost price of the chair = $$\frac{120y}{\left(100+20\right)}\times100$$

= $$\frac{120y}{120}\times100$$

= 100y

If the chair is sold at a discount of 30%, then Selling price of the chair = 150y of (100-30)%

= 150y of 70%

= $$150y\times\frac{70}{100}$$

= 105y

then profit = $$\frac{\left(selling\ price-\cos t\ price\right)}{\cos t\ price}\times100$$

= $$\frac{\left(105y-100y\right)}{100y}\times100$$