To travel from home to office, Ken has to take half-hour trains, 15-minute bus and 10-minute walk. It is known that the average of the trains is a km/h, the average speed of the bus is b km/h and his average walking speed is c km/h.
(a) Find the length of the route by each means of transport.
(b)Find the length of the route of Ken from home to office.
雖然題目寫了只翻譯就可以,但是也請各位會做這條題目的人留下它的解法,就是怎麼做那道題。