Question 530513
the distance traveled by both planes is the same when the second plane passes the first

let it be x miles

Plane I

time = x/550 

Plane II
time = x/650

x/550-x/650= 1/2 

multiply equation by 2

x/275 -x/325=1

Multiply the equation by 225*325 which is the LCD

325x-275x=275*325
50x= 89375
x=  1787.5 miles 

m.ananth@hotmail.ca