[求助] 求解 已有2人参与

2楼: Originally posted by wurongjun at 2015-09-11 08:55:58
全错的:
>> qc=0.05*0.2*0.21*0.26*0.15
qc =
  8.1900e-005
对一道的:
>> dy=0.95*0.2*0.21*0.26*0.15+0.05*0.8*0.21*0.26*0.15+0.05*0.2*0.79*0.26*0.15+0.05*0.2*0.21*0.74*0.15+0.05*0.2*0.21 ...

5楼: Originally posted by ddcy at 2015-09-14 07:41:37
这好像不是概率题，似是求最小交集的问题。无论对于做对了几道题的情形（例如所有做对3道题的情况），都必有0.26的人做错第4道题，所以做对3题或3题以上至少有26%。我这么考虑问题对不对啊？
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