An air traffic controller spots two airplanes at the same altitude converging to a point as they fly at right angles to each other. One airplane is150milesfrom the point and has a speed of600milesper hour. The other is200milesfrom the point and has a speed of800milesper hour.

a) At what rate is the distance between the planes changing?

b)How much time does the controller have to get one of the airplanes on a different flight path?