There has been successive increases of 30% and then 20% in the price of gas from the previous month. By what percentage should a driver reduce gas consumption so that the expenditure does not change? Select the correct option:
A) 20%	B) 24%	C) 28%	D) 32%	E) 36%
Let P be the original price per unit of gas.   Let x be the original gas consumption.   Let y be the reduced gas consumption.   y*1.2*1.3*P = x*P   y = x / (1.2*1.3) which is about 0.64x which is a decrease of about 36%.   The answer is 36%.
<result>E</result>
There has been successive increases of 30% and then 20% in the price of gas from the previous month. By what percentage should a driver reduce gas consumption so that the expenditure does not change?