| 聽說你也是學數學的， 做做這個: |
| 送交者: 要飯花子 2008月09月06日19:24:55 於 [詩詞歌賦] 發送悄悄話 |
| 回 答: 由 於 |
|
2 boys who live 14 miles apart start at noon to walk toward each other at rates of 3 mph and 4 mph respectively.
One boy has a dog joining their walking game at rate of 5.5 mph at the same starting time. The dog runs faster than boys walk. Once it meets the other boy, it returns immediately. Then, the dog returns again once it meets the master. So the dog runs back and forth between two boys until two boys meet. Question: how many miles has the dog run when 2 boys meet? |
|
|
|
|
 | ||||||||
|
 |
| 實用資訊 | |
