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. 12Answer: E How to calculate?
Answer: E How to calculate?作者: 驴在飞 时间: 2009-12-29 10:43
设X用X天完成W，则Y需要X－2天。 (1/x+1/(x-2))*3=5/4,求得X＝6。 完成2W的时间则为12作者: meckychen 时间: 2009-12-29 11:50
这个方程解不出来呢？作者: 疯婆子颠三 时间: 2013-7-4 10:47
解这个方程是用求根公式吗？但是数字很大啊，真要手算起来很浪费时间啊
