<PRE><B>Question 229775</B>
 Morales traveled 1600 miles by commercial jet from Kansas City, Missouri, to Spokane, Washington. 
He then traveled an additional 500 miles on a private propeller plane from Spokane to Billings, Montana.
 If the speed of the jet was 4 times the speed of the propeller plane and the
 total time in the air was 6 hours, determine the speed of each plane.
:
Let s = speed of the propeller plane
then
4s = speed of the jet
:
Write a time equation, Time = {{{dist/speed}}}
:
Jet time + prop time = 6 hrs
{{{1600/(4s)}}} + {{{500/s}}} = 6 hrs 
:
Multiply equation by 4s to get rid of he denominators, results:
1600 + 4(500) = 6(4s)
1600 + 2000 = 24s
3600 = 24s
s = {{{3600/24}}}
s = 150 mph speed of the prop
then
4(150) = 600 mph speed of the jet
;
:
Check solutions
1600/600 = 2.67 hrs
500/150  = 3.33 hrs
-------------------
Total time:6 hrs
</PRE>