Math
posted by Jenny .
A jet leaves an airport traveling at a steady rate of 600 km/h. Another jet leaves the same airport 3/4 hr later taveling at 800 km/$ in the same direction. How long will it take the second jet to overtake the first.

RT = D (rate x time = distance)
800 = rate of 2nd jet
T = time of 2nd jet
800T = distance of 2nd jet
600 = rate of 1st jet
T + .75 = time of 1st jet (3/4h = .75h)
600(T + .75) = distance of 1st jet
Distances are equal
600(T + .75) = 800T
Solve for T 
2 hours and 25 minutes