You're good if you can get these two:
- Two planes are flying at 32,000 feet moving directly toward a point above a control tower. The first plane is 100 miles from being directly above the tower and the second is 220 miles from being directly over the tower. The angle between them is 120 degrees. If the first plane is moving at 320 mph and the second plane is moving at 400 mph, how fast is the distance between the two planes decreasing (see figure 1)?
(Click to enlarge)