Every year, the price of commodity X grows by 40 paise, whereas the price of commodity Y increases by 15 paise. If the price of commodity X was Rs. 4.20 in 2001 and the price of commodity Y was Rs. 6.30 in 2001, in which year would commodity X cost 40 paise higher than commodity Y?
A. 2010
B. 2011
C. 2012
D. 2013
Answer:B
Every year, the price of commodity X grows by 40 paise, whereas the price of commodity Y increases by 15 paise. If the price of commodity X was Rs. 4.20 in 2001 and the price of commodity Y was Rs. 6.30 in 2001, in which year would commodity X cost 40 paise higher than commodity Y?
A. 2010 B. 2011 C. 2012 D. 2013
Explanation: Assume that after z years, commodity X will cost 40 paise more than commodity Y.The result is that (4.20 + 0.40z) - (6.30 + 0.15z) = 0.40.0.25z is equal to 0.40 + 2.10.2.50/0.25 = 250/25 = 10.After ten years, in 2011, X will cost 40 pence more than Y.