The price of commodity X increases by 40 paise every year, while the price of commodity Y increases by 15 paise every year. If in 2001, the price of commodity X was Rs. 4.20 and that of Y was Rs. 6.30, in which year commodity X will cost 40 paise more than the commodity Y?
Correct Answer: 2011
Explanation:
Suppose commodity X will cost 40 paise more than Y after z years.
Then, (4.20 + 0.40z) - (6.30 + 0.15z) = 0.40
⟹ 0.25z = 0.40 + 2.10
⟹ z =
2.50
=
250
= 10.
0.25
25
∴ X will cost 40 paise more than Y 10 years after 2001 i.e., 2011.
