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## rates

This topic has 1 member reply
yvonne12 Master | Next Rank: 500 Posts
Joined
07 Feb 2007
Posted:
144 messages

#### rates

Sun Mar 04, 2007 12:20 pm
Elapsed Time: 00:00
• Lap #[LAPCOUNT] ([LAPTIME])
I want to know if I did this right.

six machines working at a constant rate together can complete 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 8 days?

ans 3
6/x = x/8 cross multiply and get 3

is this correct?

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jayhawk2001 Community Manager
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Sun Mar 04, 2007 6:03 pm
Use the standard rate-formula to solve this

6 machines complete the job in 12 days, so
6 * 1/x = 1/12, so x = 72

n additional machines complete the job in 8 days
(n+6) * 1/72 = 1/8

So, n = 3

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