送交者: Enlighten 于 2008-07-31, 11:14:39:

回答: you are right, not in 3 year, die after year 3 = survive 3 years, should be 6/7. 由 chouqilozi 于 2008-07-31, 11:08:33:

• 我也是因为这么想误读原题的，换句话说如过第一年的存活率是100%那么 - chouqilozi (20 bytes) 2008-07-31, 11:36:37 (246792)

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