Question

The Garcia family has two cars. Last week, the first car consumed 30 gallons of gas and the second consumed 25 gallons of gas. The two cars drove a combined total of 1,250 miles, and the sum of their fuel efficiencies was 45 miles per gallon. What was the fuel efficiency of each of the cars last week?

Answer 1

25 and 20 milies/gallons

Explanation:

Let the fuell efficientcy of the first and the second car be f and s in gallons/miles.

Then the distance traveled by car 1 is 30 f and the car 2 is 25 s.

Since we also know that 1250 is the total distance traveled then

30 f + 25 s = 1250 (1)

Moreover we know that the efficiency is 45 miles/gallon. Hence

f + s = 45

Multiply by 30 we have

30 f + 30 s = 1350 (2)

Subtract the (1) equation from (2) we have

5s = 100

s = 20

f + 20 =45

f = 25

So the efficiency of the first car is 25 miles/gallons while the second one is 20 miles/gallons.