A family has two cars. The first car has a fuel efficiency of 40 miles per gallon of gas and the second has a fuel efficiency of 30 miles per gallon of gas. During one particular week, the two cars went a combined total of 1250 miles, for a total gas consumption of 35 gallons. How many gallons were consumed by each of the two cars that week?

Question

A family has two cars. The first car has a fuel efficiency of 40 miles per gallon of gas and the second has a fuel efficiency of 30 miles per gallon of gas. During one particular week, the two cars went a combined total of 1250 miles, for a total gas consumption of 35 gallons. How many gallons were consumed by each of the two cars that week?

Answer 1

Reiny already answered you.

http://www.jiskha.com/display.cgi?id=1390095075

Why did you post this again?

Answer 2

To calculate the number of gallons consumed by each car, we can set up a system of equations based on the given information.

Let's assume the first car consumed 'x' gallons of gas, and the second car consumed 'y' gallons of gas.

From the problem, we are given the following information:
- The first car has a fuel efficiency of 40 miles per gallon.
- The second car has a fuel efficiency of 30 miles per gallon.
- The combined total distance covered by both cars is 1250 miles.
- The total gas consumption is 35 gallons.

Since the fuel efficiency is defined as miles per gallon, we can calculate the total distance covered by each car by multiplying their fuel efficiency by the number of gallons consumed. This leads us to the equations:

1st car's distance: 40x
2nd car's distance: 30y

According to the problem, the combined distance covered by both cars is 1250 miles. So, we can write the equation:

40x + 30y = 1250 (equation 1)

Additionally, the total gas consumption by both cars is 35 gallons. So, we have another equation:

x + y = 35 (equation 2)

To solve this system of equations, we can use substitution or elimination method.

Let's solve it using the elimination method:

From equation 2, we can rewrite it as:
x = 35 - y

Now, substitute this value in equation 1:

40(35 - y) + 30y = 1250

Now, simplify the equation:

1400 - 40y + 30y = 1250
-10y = 1250 - 1400
-10y = -150

Dividing both sides by -10 gives us:

y = -150 / -10
y = 15

Now, substitute this value back into equation 2 to find x:

x + 15 = 35
x = 35 - 15
x = 20

Therefore, the first car consumed 20 gallons of gas, and the second car consumed 15 gallons of gas during that week.