20.75 because if you add 4.85+7.95+7.95 add that you get 20.75
161.5 miles / 3.5 hrs = 46.143 mph
1.666666666666667 to be exact, but rounded it is 1.66
If you're asking the difference between 14 ft and 21 ft your answer is 7 ft, just subtract 14 from 21
B. Lost 850 ft
800-450= 350
1200-350=850
I hope I helped :D