How long will the airplanes take to pass each other?

Question

Airplane 1 leaves city A for city B at the same time airplane 2 leaves city B for city A. The distance from city A to city B is 560 miles. If airplane 1 travels at 550 miles per hour and airplane 2 travels at 570 miles per hour, how long into their flights will the two planes pass each other?

Answer 1

let the time taken for the planes to meet be t

 

distance = velocity * time

 

560 = 550*t + 570*t = 1120*t

 

therefore t = 560/1120 = 0.5 hour