Answer:
275/20 = 55/4 = 13 3/4 = 13.75
12 !
Take the inverse cube root to get answer or to the 1/3 power:
1728^ (1/3) = 12
The lower square root would be 4.2
So you need to figure out how many hours per mile you need to travel to reach your destination. If you do 320/5.5 you’ll get about 58.2 mph. However you need to round this up to 59 mph to get their in time. Hope this helped!