怎樣過橋 |
送交者: hs12345 2005年10月28日11:09:41 於 [靈機一動] 發送悄悄話 |
An old man was ordered to keep anybody from crossing a bridge. It takes 10 minutes for one to walk through the bridge. The old man sits at the middle of the bridge and often takes a nap for 5 minutes. How to cross the bridge by walking?
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實用資訊 | |