You are not logged in.
Post a reply
Topic review (newest first)
- bobbym
- 2013-01-22 10:49:22
Hi;
There are many ways to solve a problem. That should be enough to make the OP happy!
- phrontister
- 2013-01-22 10:37:23
Hi,
Nice and compact, Bobby! 
I didn't think of going that way.
This is how I've done it:
Initially...
Copper = 20% of 200 lbs = 40 lbs
Magnesium = 40% of 200 lbs = 80 lbs
Other = 40% of 200 lbs = 80 lbs
Totals = 100% = 200 lbs
When added...
Copper = 24% of x lbs
Magnesium = 40% of x lbs
Other = 26% of x lbs, ∴ x = 80/26% lbs
Total = 100%
Copper added = 24% of x = (24*80/26)-40 lbs = (960/13)-40 = 440/13
Magnesium added = 50% of x = (50*80/26)-80 lbs = (2000/13)-80 = 960/13
- bobbym
- 2013-01-21 23:47:33
Hi;
Let c be the amount of copper to be added and m the amount of magnesium to be added
c = 440 / 13, m = 960 / 13
- kjames
- 2013-01-21 22:47:42
Thanks for giving time in answering my question but can somebody else show me the solution so that I can learn how to do it..thank you!
- phrontister
- 2013-01-21 22:38:33
Hi kjames,
Sorry, but I'm tied up doing something else for quite a while, and so I can only give a quick answer that isn't exact (it's a decimal approximation), and as I got it with Excel's Goal Seek I can't give the method you probably want, either.
Here's what I got:
Copper: add 33.846153846154 lbs
Magnesium: add 73.846153846154 lbs
- kjames
- 2013-01-21 21:39:12
How much copper and how much magnesium should be added to 200 lbs of an alloy containing 20% copper and 40% magnesium to produce an alloy containing 24%copper and 50% magnesium?