In the question, the car uses 3t gallons to travel 5 miles .
It means, for 1 mile , the car need
[tex] \frac{3t}{5}gallons [/tex]
Therefore, for 8 miles, the car need
[tex] \frac{3t}{5}*8 = \frac{24t}{5}gallons [/tex]
And that's the required answer .