A worm crawls from point A, due north along a straight path at a rate of 3 cm per second. A minute later, an ant leaves from point A, crawling due south at 8 cm per second. Fifteen minutes after the worm's departure how many centimeters apart from each other are the worm and the ant?
After 15 minutes the worm will be 15*60*3=2700 cm out of point A. 8-3=5 cm the ant is gaining on the worm each second. 2700/300=9 minutes.