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?  Answers.
A) 2010	B) 2001	C) 2012	D) 2011	E) 2009
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">6.3 - 4.2</gadget>
<output>2.1</output>

<gadget id="calculator">(2/5) + 2.1</gadget>
<output>2.5</output>

<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">(2/5) - (3/20)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">2.5 / (1/4)</gadget>
<output>10</output>

<gadget id="calculator">2_001 + 10</gadget>
<output>2_011</output>

<result>D</result>
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?
add(2001, divide(add(divide(40, const_100), subtract(6.30, 4.20)), subtract(divide(40, const_100), divide(15, const_100))))
"suppose commodity x will cost 40 paise more than y after z years . then , ( 4.20 + 0.40 z ) - ( 6.30 + 0.15 z ) = 0.40 0.25 z = 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 . , 2011 . answer is d ."