<PRE><B>Question 75165</B>
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
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