I try by strict Math, the anwser should be between 78 and 81

来源: 于 2012-01-03 12:09:54 [旧帖] [给我悄悄话] 本文已被阅读：次

the back times are longer.Cs we have to use small number in the dinominatod the error is big. If the anwser is 81,we also can't use your formula....