There is a decrease of 10% yearly on an article. If this article was bought 3 years ago and present cost is Rs. 5,832 then what was the cost of article at buying time?
A. Rs. 7,200
B. Rs. 7,862
C. Rs. 8,000
D. Rs. 8,500
Answer: Option C
Solution (By Examveda Team)
$$A = P {\left( {1 - \frac{R}{{100}}} \right)^n}$$Where A = Value of goods after n years
P = Initial Price
R = Rate of depriciation
$$\eqalign{ & \therefore P = \frac{{5832}}{{{{\left( {1 - \frac{{10}}{{100}}} \right)}^3}}} \cr & \Rightarrow P = \frac{{5832}}{{{{\left( {1 - \frac{1}{{10}}} \right)}^3}}} \cr & \Rightarrow P = \frac{{5832}}{{{{\left( {\frac{9}{{10}}} \right)}^3}}} \cr & \Rightarrow P = 5832 \times \frac{{10}}{9} \times \frac{{10}}{9} \times \frac{{10}}{9} \cr & \Rightarrow P = 8000 \cr} $$

Plz solution the question
5832*100*100*100/90*90*90= 8000
Ans:C
5832*(10/9)*(10/9)*(10/9)=8000
Answer option is C.
use effective percent formula for 10% for three years
we got 27.1% decreased worth of article
100-27.1=72.9=present worth of article
72.9=Rs.5832
100=Rs.x
by cross multiplication
x=(5832*100)/72.9
we get,
x=8000=worth of article three years ago.