Running at their respective constant rate, machine X takes 2 days longer to produce w widgets than machines Y. AT these rates, if the two machines together produce 5w/4 widgets in 3 days, how many days would it take machine X alone to produce 6w widgets.
Options:
A) 4  B) 36  C) 8  D) 10  E) 12
I am getting 12. E. Hope havent done any calculation errors..   approach..   let y=no. of days taken by Y to do w widgets. Then X will take y+2 days.   1/(y+2) +1/y = 5/12(5/12 is because (5/4)w widgets are done in 3 days. So, x widgets will be done in 12/5 days or 5/12 th of a widget in a day)   Solving, we have y = 4   =&gt;X takes 6 days to doing x widgets. So, he will take 36 days to doing 6w widgets.   Answer : 36
<result>B</result>
Running at their respective constant rate, machine X takes 2 days longer to produce w widgets than machines Y. AT these rates, if the two machines together produce 5w/4 widgets in 3 days, how many days would it take machine X alone to produce 6w widgets.