Question

An item marked at $Rs.840$ is sold for $Rs.714$. Find the rate of discount:
A) $10\% $
B) $15\% $
C) $5\% $
D) $25\% $

Answer 1

Hint: We know when someone buys the product for some money it is called cost price ($CP$) and when they sell it, it is called selling price ($SP$). So a discount is given when $CP$ is greater than $SP$. And discount rate$ = \dfrac{{CP - SP}}{{CP}} \times 100$

Complete step-by-step answer:
So the question is saying that there is an item which is marked at $Rs.840$. This means that item has an MRP of $Rs.840$. This means that the shopkeeper purchased it for $Rs.840$, that is, it is the cost price.
Now, according to question, we are given that the item is sold for $Rs.714$. And we have to find the discount rate.
So as we know the MRP or cost price of the item is $Rs.840$, and then it is sold for $Rs.714$.
So the selling price is given, that is , $Rs.714$.
Now, we know that selling price is less than cost price. That means a discount is given on that item. So we need to find out the discount rate on that item.
So discount rate is given by
discount rate$ = \dfrac{{CP - SP}}{{CP}} \times 100$
we know cost price ($CP$)$ = Rs.840$
selling price ($SP$)$ = Rs.714$
discount rate$ = \dfrac{{CP - SP}}{{CP}} \times 100$
$
   = \dfrac{{840 - 714}}{{840}} \times 100 \\
   = 15\% \\
 $
So this item is sold at $15\% $ discount rate on MRP.
So option B is correct.

Note: Discount can only be given when the cost price or MRP is greater than the selling price or if discount and $CP$ is given. Then $SP$ would be given by
$SP = CP - \dfrac{{CP \times discount}}{{100}}$