If a merchant offers a discount of 10% on the list price, then she makes a loss of 25%. What % profit or % loss will she make if she sells at a discount of 20% of the list price?

Let list price = Rs. $$100x$$

After 10% discount, selling price = $$\frac{100 - 10}{100} \times 100x$$ = Rs. $$90x$$

Let Cost price = Rs. $$y$$

=> Loss % = $$\frac{y - 90x}{y} \times 100 = 25$$

=> $$\frac{y - 90x}{y} = \frac{25}{100} = \frac{1}{4}$$

=> $$4y - 360x = y$$

=> $$4y - y = 360x$$

=> $$y = \frac{360x}{3} = 120x$$

If discount = 20%, => Selling price = $$\frac{100 - 20}{100} \times 100x = Rs. 80x$$

$$\therefore$$ Loss % = $$\frac{120x - 80x}{120x} \times 100$$

= $$\frac{100}{3} \approx 33.33 \%$$

=> Ans - (B)