GMAT Prep # 21

This topic has expert replies
Newbie | Next Rank: 10 Posts
Posts: 6
Joined: Sun Aug 05, 2007 4:12 pm

GMAT Prep # 21

by Steve Hwang » Fri Nov 02, 2007 10:22 am
21. Six machines, each working at the constant rate, together cna compete a certain job in 12 days. How many additional machines, each working at the same constant rate, will be needed to complete the job in 8days?

2 days
3 days
4 days
6 days
8 days
Attachments
GMAT Prep test1.Q21.jpg

Master | Next Rank: 500 Posts
Posts: 258
Joined: Mon Aug 27, 2007 12:43 pm
Thanked: 15 times

by ri2007 » Fri Nov 02, 2007 11:45 am
6 machines take 12 days, so u need 9 machines to complete the job in 8 days
i.e 3 machines more
so ans is b

Newbie | Next Rank: 10 Posts
Posts: 6
Joined: Sun Aug 05, 2007 4:12 pm

Got it

by Steve Hwang » Fri Nov 02, 2007 1:13 pm
I just understand this question correctly...

thanks for your explanation.