The price of an article was increased by r%. Later the new price was decreased by r%. If the latest price was Rs. 1, then the original price was :

A. Rs. 1

B. Rs. $$\frac{{1 - {r^2}}}{{100}}$$

C. Rs. $$\frac{{\sqrt {1 - {r^2}} }}{{100}}$$

D. Rs. $$\left( {\frac{{10000}}{{10000 - {r^2}}}} \right)$$

Answer: Option D

Solution(By Examveda Team)

r% = $$\frac{r}{100}$$

Initial Price		Final
100		(100 + r)
100		(100 - r)
10000		(100 + r) (100 - r)

According to the question,
(100 + r) (100 - r) units = Rs. 1
(10000 - r²) units = Rs. 1
1 unit = $$\left( {\frac{{1}}{{10000 - {r^2}}}} \right)$$
Original price = $$\left( {\frac{{10000}}{{10000 - {r^2}}}} \right)$$