<PRE><B>Question 186698</B>
A certain trip took 40 min to complete. If half the distance was 100 and 
the other half at 60, what&#39;s the distance traveled during the trip?
:
Let d = half the distance
:
Write a time equation: (Time = dist/speed)  Change 40 min to {{{2/3}}} hr
:
{{{d/100}}} + {{{d/60}}} = {{{2/3}}}
Multiply equation by 300
300*{{{d/100}}} + 300*{{{d/60}}} = 300*{{{2/3}}}
Results:
3d + 5d = 100(2)
8d = 200
d = {{{200/8}}}
d = 25 mi is half the dist
obviously
50 mi is the total distance
;
;
Check solution; find the times at each speed:
25/100 = .25 hr
25/60 =  .4167 hr
----------------
total = .667 hr which is 40 min</PRE>