Question

The original price of a music CD is Rs.500. A shopkeeper offers a \[10\% \] discount on this music CD and then again offers a \[20\% \] discount on the new price. How much will you have to pay, finally?
A. 160
B. 260
C. 360
D. 460

Answer 1

Hint: At first we’ll find the price of the music CD by subtracting the \[10\% \]of the original price from the original price, now we have the new price of the CD. Again we’ll find the latest price of the music CD by subtracting \[20\% \] of the new price from the new price. Now, the current price is the amount we’ve to pay to buy that music CD.

Complete step by step Answer:

Given data: original price of music CD=Rs.500
At first, he offered \[10\% \] and then \[20\% \] on the new price
\[10\% \] of the original price of the music CD$ = 10\% of 500$
$ = \dfrac{{10}}{{100}} \times 500$
Dividing by 100 on numerator and denominator, we get,
$ = 50$
Therefore the new price of the music CD is the original price minus \[10\% \] of the original price, i.e.,
The new price of the music CD$ = 500 - 50$
Hence, the new price of the music CD$ = Rs.450$.
Now, \[20\% \] of the new price of the music CD$ = 20\% of450$
$ = \dfrac{{20}}{{100}} \times 450$
 Dividing by 100 on numerator and denominator, we get,
$ = 90$
Therefore the latest price of the music CD is new price minus \[20\% \] of new price, i.e.,
The latest price of the music CD$ = 450 - 90$
Hence, the latest price of the music CD$ = Rs.360$
Therefore the final price of the music CD$ = Rs.360$
Hence the correct option is D.

Note: Most of the student simply subtract \[\left( {10 + 20} \right)\% \]of the original price to get the answer, avoid doing this as it is clearly given that the new discount is on the new price, not the original price, so finding an answer like this will get us the wrong answer only.