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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
Written by Take GMAT Team on July 4th, 2009 with
19 comments.
Read more articles on GMAT Problem Solving and GMAT Question of the Day.
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
Written by Take GMAT Team on July 4th, 2009 with
19 comments.
Read more articles on GMAT Problem Solving and GMAT Question of the Day.
Read the comments left by other users below, or:
abbas
#2.
July 30th, 2007, at 12:46 PM.
e
Biplav Chatterjee
#3.
July 30th, 2007, at 1:21 PM.
E. 12
apply W/y and W/y+2 and calculate combined rate at 2W(2y+2)/y(y+2) and solve using 3 days and 5/4W to get y =4, and x=y+2=6, thus 2x=6*2=12
lucas
#4.
July 30th, 2007, at 6:13 PM.
Hi, can somebody please explain this step by step. No clue (feel stupid). thx
Jess
#5.
July 31st, 2007, at 10:40 AM.
Days M/c Y takes to make W widgets = D
Days M/c X takes to make W widgets = D+2
Rate of work done by X = W/(D+2)
Rate of work done by Y = W/(D)
Combined rate of work = 1/(D+2) + 1/D = 2((D+1)W)/(D(D+2))
5W/4 widgets made in 3 days by the two m/cs, so rate = 5W/12
5W/12 = 2((D+1)W)/(D(D+2)
On solving gives D=4 ==> rate of X = 4+2 = 6. So to make 2W widgets it needs 12 days.
animesh
#6.
August 1st, 2007, at 10:10 PM.
e
AP
#7.
August 2nd, 2007, at 11:51 PM.
e
shilpa
#8.
August 26th, 2008, at 11:47 PM.
E
Binita
#9.
July 4th, 2009, at 7:53 PM.
E
Anubhav Goyal
#10.
July 6th, 2009, at 9:53 PM.
e
anand
#11.
July 7th, 2009, at 11:30 AM.
e
krishna74
#12.
July 7th, 2009, at 2:50 PM.
E : 12 days
Shal
#13.
July 10th, 2009, at 10:39 AM.
12
soumyajit
#14.
July 13th, 2009, at 3:41 PM.
Ans. e
dharm
#15.
July 15th, 2009, at 3:09 PM.
Option C
GG
#16.
July 15th, 2009, at 11:38 PM.
E
Dharm
#17.
July 17th, 2009, at 12:54 PM.
Sorry it’s Option E only
Deepak Yadav
#18.
July 18th, 2009, at 9:56 PM.
E
Let machine Y takes U days to complete the work W.
So work done by Y in one day = W/U
work done by X in one day = W/(U+2)
Total work done in one day= W(1/U + 1/U+2) = W 5/4 * 1/3
solve it
Deepak
#19.
July 21st, 2009, at 4:43 PM.
E
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#1. July 30th, 2007, at 12:21 PM.
e