So, in 240 miles can be made by 2 hours.
Do this equation:
240 × 2 = 480 / 4 hours.
You cannot do 3 because it won't fit another 240 miles.
Next, subtract the 480 miles from 600 miles.
600 - 480 = 120
Also, if you would've divided by 2 hours.
240 ÷ 2 = 120 / 1 hour
Add the hours.
4 + 1 = 5 hours
It takes 5 hours to travel 600 miles by the small plane.