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 :

Answer: Option D

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 = $$\left(\frac{10000}{10000-r^2}\right)$$