作者windhsu (小太極)
看板Inference
標題[問題] 一個數學問題
時間Wed Sep 2 02:28:05 2009
x1,x2,x3合力做一工程需花n個小時,x2和x3合力做此工程要花m個小時,若rate不變,
問x1單獨做需多久時間
請問這一題該怎麼算?
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1F:推 werul:T=n(x1+x2+x3)=m(x2+x3)=>T/x1=n/(m-n)(x2+x3) 09/02 03:16
2F:推 werul:上面算式好像錯了 不要裡我 09/02 03:19
3F:推 teves:1/(1/n-1/m) = nm/(m-n) 09/02 09:01
4F:推 BGirlAlu:mn/(m-n) 09/02 12:07