Solution:
Here:
On 12 gallons of gas 144 miles is travelled.
So, for 1 mile :
[tex] \frac{12}{144} \: gallons \: of \: gas[/tex]
[tex] = \frac{1}{12} \: gallons \: of \: gas[/tex]
is required.
Now,
for 240 miles:
[tex] \frac{1}{12} \times 240[/tex]
[tex] = 20 \: gallons \: of \: gas[/tex]
is required.
But, according to question, the tank only contains 6 gallons of gas. So, see needs more (20 - 6) gallons of gas [i.e. 14 gallons of gas].
