Gasoline varies in cost from $0.93 to $1.13 per gallon. If a car’s mileage varies from 16 to 24 miles per gallon, what is the difference between the most and least that the gasoline for a 480-mile trip will cost? Choose the correct choice from the following choices
A) $15.13	B) $15.30	C) $15.72	D) $16.01	E) $16.23
Solution:   We know that the per gallon cost of gasoline varies from $0.93 - $1.13.   Now we want to find the MAXIMUM difference between the least amount of money spent on gasoline and the largest amount of money spent i.e. to calculate max. trip cost - min. trip cost.   Mileage is given to be 16 to 24 miles per gallon, thus to travel 480 miles you will need gasoline in the range 480/24 to 480/16 which is 20 to 30 gallons.   So, for these 20 gallons and 30 gallons of gasoline the cost is as follows: (divide this task into 2 parts, 1 for 30 gallons and 2nd one for 20 gallons).   Case 1: for 30 gallons the cost is 30*0.93 to 30*1.13 which is $27.90 to $33.90   Case 2: for 20 gallons the cost is 20*0.93 to 20*1.13 which is $18.60 to $22.60   Thus, the maximum cost of the 480 mile trip is $33.90 and minimum is $18.60   so the difference is $33.90 - $18.60 = $15.30   Answer: $15.30 33.90 -  18.60= 
<gadget id="calculator"> 33.90 -  18.60</gadget>
<output>15.3</output>
$15.30   Answer: $15.30
<result>B</result>
Gasoline varies in cost from $0.93 to $1.13 per gallon. If a car’s mileage varies from 16 to 24 miles per gallon, what is the difference between the most and least that the gasoline for a 480-mile trip will cost?