Bunuel wrote:
Bob’s pickup truck averages 20 miles/gallon. If Bob fills the 12-gallon gas tank to capacity, how many miles can he travel once the ratio of unused gas to used gas is 3:1?
Let us consider Bob uses x gallons
Therefore we can set the ratio as -
\(\frac{(12-x)}{x} =\frac{3}{1}\) (since 12 gallons is full tank and (12-x) is the unused gas)
or \(x= 3\).
Now we have to consider in the ratio of \(\frac{3}{1}\)
i.e \(\frac{3x}{x} = \frac{9}{3}\) (putting the value of x = 3, because we have assumed he uses x gallons and so in every 3parts used gas we have 9 parts unsed gas)
Therefore Bob can travel with 9 gallons remaining fuel = 9*20 = 180 miles