Question

Sarah wants to buy the car that has a better mileage rating. Cars of Company A travel 20 miles per gallon and cars of Company B travel 14 km per liter.

[1 mile = 1.6 km; 1 gallon = 3.79 liters]

Part A: Which company's car should Sarah buy? Justify your answer by comparing the mileages after converting to the same units. (5 points)

Part B: If 10 gallons of gas is filled in the car which gives better mileage, and you went on a drive and checked on the gas used every 30 miles, describe appropriate scales on the x-axis and y-axis to graph the rate at which the car uses gas. (5 points)

Answer 1

Hello, let me begin with part A. I am assuming Sarah wants to buy the car with a better gas mileage, so in order to deduce which gas mileage is higher, you need to convert one of them to the other's units using the conversion factor

I will convert #2 into mpg.

14km/liter * 3.97liter/gallon = 55.58 km/gallon
55.58km/gallon * 1mile/1.6km = 34.7375 mile/gallon

Answer 2

In part B, the independent (x) variable is going to be the times that you are checking your tank (t), and will be on your x-axis. Your y-axis will be dependent on how many past checks you have completed, and therefore your dependent variable will be the gallons of gas left in the tank. Since your tank would begin with 10 gallons, your y-axis should be between 0<y<10 and you will run out of gas after you go a certain distance.

This distance will be once you have used up all your gas from 10 gallons of gas which will allow you to drive 10*34.7375=347.375miles. If you are checking every 30 miles, the maximum times you can check is just under 12, so the x axis should be between 0<x<12.

Hope this helped you :)

Answer 3

yes it helped me a lot.. thank you!!!! @kuggy