Question

The cost of an article goes down every year by 10% of its previous value. Find its original cost if the cost of it after 2 years is ₹24,300?

• A. 26,000
• B. ₹33,700
• C. ₹35,000
• D. ₹30,000

Answer 1

The correct option is D ₹30,000

The cost decreases 10% per year.
let the cost at the beginning of the first year be ₹100
then, at the beginning of the second year it will be = 100 - 10% of 100 = ₹90
and, at the beginning of third year, C.P will be = 90 - 10% of 90 = ₹81

Let the original cost be ₹ a
So, a : 100 :: 24,300 : 81
(ratio of the original cost = ratio of cost after two years)

Product of means = Product of extremes

$\Rightarrow$ 24,300 $\times$ 100 = a $\times$ 81

$\Rightarrow$ a = $\frac{24,300\times 100}{81}$

$\Rightarrow$ a = 30,000

Thus, the original cost of the article was ₹30,000