The balance of a trader weighs 10% less than it should. Still the trader marks up his goods to get an overall profit of 30%. What is the mark up on the cost price?
Choose the correct choice from the following options:  A) 40%  B) 8%  C) 25%  D) 17%  E) 9%
The most natural way to deal with 'weights' questions is by assuming values.   Say the trader's balance shows 100 gms. It is actually 90 gms because it weighs 10% less. Say, the cost price is $90 ($1/gm). Since he gets a profit of 30%, the selling price must be 90+(30/100)*90= 
<gadget id="calculator">90+(30/100)*90</gadget>
<output>117</output>
$117   Since the cost price is actually supposed to be $100 (for 100 gms) and the selling price is $117, the mark up is simply 17%.   Ans : 17%
<result>D</result>
The balance of a trader weighs 10% less than it should. Still the trader marks up his goods to get an overall profit of 30%. What is the mark up on the cost price?