Question

Mary drove 380 miles using 14 gallons of gas. At this rate, how many gallons of gas would she need to drive

418 miles?
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Answer 1

She will need 15.4 gallons to drive 418 miles

Explanation:

Step 1

Consider the expression below;

T=G×N

where;

T-total miles traveled

G-number of miles per gallon

N=quantity of gas consumed

This can also be expressed as;

Total miles=number of miles per gallon×number of gallons

In our case;

T=380 miles

G=unknown

N=14 gallons

replacing;

380=G×14

14 G=380

G=380/14

G=27.14 miles per gallon

Step 2

Using the same expression;

T=G×N

where;

T=418 miles

G=27.14 miles per gallon

N=unknown

replacing;

418=27.14×N

27.14 N=418

N=418/27.14

N=15.4 gallons

She will need 15.4 gallons to drive 418 miles