Set up a proportion:
[tex] \frac{1}{80} = \frac{x}{320} [/tex]
Cross multiply:
[tex]80x = 320[/tex]
Divide both sides by 80 to isolate x:
[tex]x = 4[/tex]
It takes four hours to travel to a location 320km away. Furthermore, it would take 8 hours to go to that location and return.
