1.  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 ₹ 4.20 and that of Y was ₹ 6.30, in which year commodity X will cost 40 paise more than the commodity?
A. 2011
B. 2012
C. 2013
D. 2010

Answer: Option B

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= 2.50/0.25 = 250/25

=10

Therefore X will cost 40 paise more than Y 10 years after 2001 .

i.e in 2011