PP1-PS-89

[mupeane]

A company has two types of machines, type R and type S. Operating at a constan rate, a machine of type R does a certaibn job in 36 hours and a machine of type S does the same job in 18 hours. If the company used the same number of each type of machine to do the job in 2 hours, how many machines of type R were used?

Ans: 9 hours

請大家幫幫忙囉～～～～

[小花]

(A) 3
(B) 4
(C) 6
(D) 9
(E) 12

1/18+1/36=1/12
R+S完成工作需 12小時
2小時把工作完成
則需 6(R+S)

題目好像是問需要多少機器
Ans:C

[mupeane]

謝謝喔，我懂了

不好意思，答案單位給錯了