Find the rate of discount being given on an article whose selling price is rupees 315 after deducting a discount of rupees 210 on its marked price

Given:

Selling price $=Rs.\ 315$

Discount on marked price $=Rs.\ 210$ 

To do:

We have to find the rate of discount.

Solution:

SP $= Rs.\ 315$

Discount $= Rs.\ 210$

We know that,

Marked price $=$ SP $+$ Discount

$= 315 + 210$

$= Rs.\ 525$

This implies,

Discount % $= \frac{Discount}{Marked\ price} \times 100$

$= \frac{210}{525} \times 100$

$= 40$%

The rate of discount is 40%.