You can
put this solution on YOUR website!Let t=time it takes to travel the last 300 mi
Distance(d)=rate(r) times time (t) or d=rt; r=d/t; t=d/r
Rate of speed for first 480 mi=480/12=40 mph
For the second leg of the trip, she increased her speed by 20 mph. That would be:
40 mph+20 mph=60 mph=rate of speed for the remaining 300 mi
So t=d/r=300/60=5 hrs--------------------ans
Hope this helps----ptaylor