Two cars, 400

400 kilometers apart, begin driving toward each other on a long, straight highway. One car travels 105

105 kilometers per hour and the other 95

95 kilometers per hour. At the same time, a canary, starting on one car, flies back and forth between the two cars as they approach each other. If the canary flies 140

requirement

140 kilometers per hour and spends no time to turn around at each car, how far has it flown when the cars collide?