Answer:
1 hour
Step-by-step explanation:
Let's assume that Patrick is travelling on a straight line throughout the whole path in order to minimize the distance.
The number of miles that he can travel on a full tank is:
[tex]m = 5\ mpg*4\ gallons\\m=20\ miles[/tex]
The distance travelled by Patrick in one hour (from 2p.m. to 3p.m.) is:
[tex]d^2=6^2+8^2\\d=\sqrt{100}\\ d=10\ miles[/tex]
If he is travelling at 10 miles per hour, and he could travel for a total of 20 miles, then the time remaining before the tank runs out of gasoline is:
[tex]t=\frac{20-10}{10}\\ t=1\ h[/tex]
If he continues at this rate, the gas will last for 1 more hour.