<PRE><B>Question 1042398</B>
A car completes a 10 mile trip in 20 minutes.
If car does 1/2 of trip at speed 20 miles/hr,
At 20 mph he completes 5 mi in 15 min; (5/20 = .25 hrs which is 15 min)
therefore
he has to complete 5 mi in the remaining 5 min 
What is the correct speed for remainder of distance?
speed = dist/time; 5 min = 1/12 hr
s = {{{5/(1/12)}}}
s = 5 * 12
s = 60 mph to complete 5 mi in 5 min 
:
Check this, find the dist at each speed (dist = time * speed)
15 min: 1/4 * 20 = 5 mi 
5 min: 1/12 * 60 = 5 mi 
-----------------
total dist 10 mi</PRE>