If the cost price of 20 articles is equal to the selling price of 40 articles, what is the % profit or loss made by the merchant?  Choose the correct choice from the following
A) 25% loss B) 25% profit C) 20% loss D) 20% profit E) 50% loss
Let the cost price of 1 article be $1.   Therefore, cost price of 20 articles = 20 * 1= 
<gadget id="calculator">20 * 1</gadget>
<output>20</output>
$20   The selling price of 40 articles= cost price of 40 articles = $40.   Now, we know the selling price of 40 articles. Let us find the cost price of 40 articles.   Cost price of 40 articles = 40 * 1= 
<gadget id="calculator">40 * 1</gadget>
<output>40</output>
$40.   Therefore, profit made on sale of 40 articles= Selling price of 40 articles - cost price of 40 articles   = 20 - 40 = -$20.   As the profit is in the negative, the merchant has made a loss of $20.   Therefore, % loss = loss/cp * 100   % loss = -20/40 * 100 = 50% loss.   50% loss
<result>E</result>
If the cost price of 20 articles is equal to the selling price of 40 articles, what is the % profit or loss made by the merchant?