Question 83079
 twin-engine plane can fly 800 mi in the same time that it takes a single-engine plane to fly 600 mi. The rate of the twin-engine plane is 50 mph faster than that of the single-engine plane. Fine the rate of the twin-engine plane.
--------------------
Twin plane DATA: 
Distance = 800 mi ; Rate = x+50 mph ; time = d/r = 800/(x+50) hrs.
-------------------
Single Plane DATA:
Distance = 600 mi ; Rate = x mph ; time = d/r = 600/x
===============
EQUATION:
time = time
800/(x+50) = 600/x
8/(x+50) = 6/x
8x = 6x + 300
x= 150 mph
x+50 = 200 mph (twin-engine plane rate)
===========================
Cheers,
Stan H.