Answer:
It takes 26 2/3 gallons to make a 400 mile trip.
Step-by-step explanation:
This question is simply asking for the number of miles per gallon . In math, <em>per</em> means this is meant to be written as a fraction.
"If a trip of 270 miles required 18 gallons of gas" is actually saying "270 miles per 18 gallons." This can be written as a fraction like so: 270/18.
If we're looking for the amount of gas used for a 400 mile trip, we have the fraction: 400/g, g being the amount of gallons it took to make that trip.
Now we can set up the proportion:
Cross multiply and solve accordingly.
400/g
So the answer is:
It takes 26 2/3 gallons to make a 400 mile trip.