<PRE><B>Question 1114986</B>
 David rode his bike east at 20 mi/hr for 36 minutes with a tailwind. He then turned around to ride home along the same route against the wind. If the return trip took 45 minutes, find the wind speed and the speed at which David pedals with no wind (to the nearest mile per hour). 
with-wind DATA:
rate = 20 mph ; time = 36/60 hrs ; distance = rate*time = 12 miles
---
Against-wind DATA:
dist = 12 miles ; time = (45/60) = 3/4 hr ; rate = dist/time = 12/(3/4) = 16 mph
-------
Equations:
bike + wind = 20 mph
bike - wind = 16 mph
-----
Add and solve for bike speed::
2b = 36
bike speed = 18 mph
------------------
Subtract and solve for wind speed
2w = 4
wind speed = 2 mph
--------------
Cheers,
Stan H.
------------</PRE>