<PRE><B>Question 181115</B>
An athlete covered a distance of 57 miles by walking for 2 hours, and then
 riding a bicycle for the remainder of the trip. His rate increased by 10 mph
 on the bike. If the entire trip took 5 1/2 hours, what was his riding rate?
:
Let s = the riding rate
then
(s-10) = the walking rate
:
From the given information, he walked 2 hrs, therefore, he biked 3.5 hr
:
Write a distance equation: dist = time * speed
Walk dist + bike dist = 57 mi
2(s-10) + 3.5s = 57
:
2s - 20 + 3.5s = 57
:
5.5s = 57 + 20
s = {{{77/5.5}}}
s = 14 mph on the bike
:
:
Check solution by finding the distances (14 - 10 = 4 mph walking):
3.5*14 = 49 mi
2 * 4  = 8 mi
-------------
total = 57 mi</PRE>