a certain car uses one gallon of gasoline every 32 miles when it travels on highway, and one gallon of gasoline every 20 miles when it travels in the city. when a car travels 4 miles on highway and 4 additional miles in the city, it uses what percent more gasoline than if it travels 8 miles on the highway? Choose the most appropriate option
A) 15 %	B) 20 %	C) 22.5 %	D) 25 %	E) 30 %
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">(1/20) * 4</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / 32</gadget>
<output>1/32 = around 0.03125</output>

<gadget id="calculator">4 * (1/32)</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">(1/5) + (1/8)</gadget>
<output>13/40 = around 0.325</output>

<gadget id="calculator">8 * (1/32)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(13/40) - (1/4)</gadget>
<output>3/40 = around 0.075</output>

<gadget id="calculator">(3/40) / (1/4)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(3/10) * 100</gadget>
<output>30</output>

<result>E</result>
a certain car uses one gallon of gasoline every 32 miles when it travels on highway, and one gallon of gasoline every 20 miles when it travels in the city. when a car travels 4 miles on highway and 4 additional miles in the city, it uses what percent more gasoline than if it travels 8 miles on the highway?
multiply(divide(subtract(add(multiply(divide(const_1, 20), 4), multiply(4, divide(const_1, 32))), multiply(8, divide(const_1, 32))), multiply(8, divide(const_1, 32))), const_100)
"4 miles on the highway = 4 / 32 gallons ; 4 miles in the city = 4 / 20 gallons ; total = 4 / 32 + 4 / 20 = 13 / 40 gallons . 8 miles on the highway = 8 / 30 gallons . the % change = ( 13 / 40 - 8 / 32 ) / ( 8 / 32 ) = 0.30 . answer : e ."