Question

12 gallons of gas to travel 144 miles. Six gallons in the tank how much more will she need to travel 240

Answer 1

Solution:
Here:
On 12 gallons of gas 144 miles is travelled.
So, for 1 mile :
$\frac{12}{144} \: gallons \: of \: gas$
$= \frac{1}{12} \: gallons \: of \: gas$
is required.
Now,
for 240 miles:
$\frac{1}{12} \times 240$
$= 20 \: gallons \: of \: gas$
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].