Running at their respective constant rates, Machine X takes 2 days longer to produce w widgets than Machine Y. At these rates, if the two machines together produce ~$5 \over 4$~ w widgets in 3 days, how many days would it take Machine X alone to produce 2W widgets?
4
6
8
10
12
结果不好算
设x用了x天做w个,y用了x-2天,则x一天做w\x,y一天w\(x-2)
3天x,y一起做了3(w\x+w\(x-2))=5\4w
解方程得到(5x-4)(x-6)=0
x1=0.8 x2=6
天数是整数,所以答案是6
机器x生产2w就需要6*2=12
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