Problema Solution
In a family thre are two cars. The sum of the average miles per gallon obtained by the two cars in a particular week is 65. the first car has consumed 20 gallons during that week, and the second has consumed 40 gallons, for a total of 1800 miles driven by the two cars combined. What was the average gas mileage obtained by each of the two cars in that week?
Answer provided by our tutors
The way to calculate these problems is to figure out what we're looking for. The two cars travel a combined 1800 miles. If you add their average MPG, you get 65. And we know that one used 20 gallons, the other 40.
So, the distance a car travels is MPG*Gallons.
Car 1: 20 Gallons * X (MPG)
Car 2: 40 Gallons * (65 - X)
It is 65 - X because when you add their total MPG, it is 65 and we have allowed car 1's MPG to be represented by X. Now, add car1 and car 2, set it equal to total miles 1800.
20X + 40 (65-X) = 1800
20X + 2600 - 40x = 1800
-20X = -800
x = 40 (that is car 1's MPG; car 2's is 65 - X)