If 5% more is gained by selling an article for Rs. 420 than by selling it for Rs. 380, the cost of the article is?  Pick one:
A) 500 B) 688 C) 200 D) 121 E) 800
Let C.P. be Rs. x.   Then, 5% of x = 420 - 380= 
<gadget id="calculator">420 - 380</gadget>
<output>40</output>
40   x/20= 40 =&gt; x = 800   Answer: 800
<result>E</result>
If 5% more is gained by selling an article for Rs. 420 than by selling it for Rs. 380, the cost of the article is?