The unit rate of 200 miles in 4 hours is 50 miles for every 1 hour.
200/4 divided by 4/4 = 50/1
The unit rate of 270 miles in 6 hours is 45 miles for every 1 hour.
270/6 divided by 6/6 = 45/1
The unit rate of 1440 miles in 30 hours is 48 miles for every 1 hour.
1440/30 divided by 30/30 = 48/1
