→ pcdiy:5/4 /(1/X + 1/X-2)=3 可求出X＝6 10/23 16:15
跟精華區的不一樣
請NN幫忙解答
Q26:
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 5/4 w widgets in 3 days, how many days would it take
machine X alone to produce 2w widgets?
A. 4
B. 6
C. 8
D. 10
E. 12
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