If the price of petrol increases by 25% and Raj intends to spend only an additional 15% on petrol, by how much will he reduce the quantity of petrol purchased?  Pick one:
A) 10% B) 12% C) 8% D) 16% E) None of these
Explanation :   Let the price of 1 litre of petrol be Rs. x and let Raj initially buys 'y' litres of petrol.   Therefore, he would have spent Rs. xy on petrol.   When the price of petrol increases by 25%, the new price per litre of petrol is 1.25x.   Raj intends to increase the amount he spends on petrol by 15%.   i.e., he is willing to spend xy+15% of xy=1.15xy.   Let, the new quantity of petrol that he can get be 'q'.   Then, 1.25x × q=1.15xy.   =&gt;q=1.15xy/1.25x.   =&gt;0.92y.   As the new quantity that he can buy is 0.92y, he gets 0.08y lesser than what he used to get earlier i.e a reduction of 8%.   Answer : 8%
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If the price of petrol increases by 25% and Raj intends to spend only an additional 15% on petrol, by how much will he reduce the quantity of petrol purchased?