Question 87878
Two planes leave Chicago-one traveling due east and the other due west. The first travels 100 miles per hour faster than the second. How long will it be until they are 2000 miles apart?
:
I think there are an infinite number of solutions to this problem 
:
Let s = speed of the slower plane
Then
(s+100) = speed of the faster plane
:
Since they going in opposite direction their relative speed = 2s+100
:
Time = dist/(2s+100)
:
Graph this (y=time; x=speed of the slower plane):
{{{ graph( 300, 200, -100, 1000, -4, 10, 2000/(2x+100)) }}}
a couple of integer examples
x = 150 mph, y = 5 hrs
x = 200 mph, y = 4 hrs
x = 450 mph, y = 2 hrs