There has been successive increases of 25% and then 10% 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) 23%	B) 27%	C) 31%	D) 35%	E) 39%
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*1.1*1.25*P = x*P   y = x / (1.1*1.25) which is about 0.73x which is a decrease of about 27%.   The answer is 27%.
<result>B</result>
There has been successive increases of 25% and then 10% 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?