Matrices...

[Smokinoakum]

.........Lead.. Zink....Copper
Alloy A..40%....30%.....30%
Alloy B..20%....30%.....50%
Alloy C..........10%.....90%
How many grams of each alloys A, B, and C must be mixed to get 325g of an alloy that is 15.2% lead, 37.2% zink, and 47.6% copper?

My answer is: Alloy A= -195g Alloy B= 637g Alloy C= -117g

I've tried this using the Matrix, and the inverse Matrix, and keep coming up with negitives on some alloys. How can one have negetive alloys?
Thanks for your help.
Neil

 

[Deleted member 4993]

.........Lead.. Zink....Copper
Alloy A..40%....30%.....30%
Alloy B..20%....30%.....50%
Alloy C..........10%.....90%
How many grams of each alloys A, B, and C must be mixed to get 325g of an alloy that is 15.2% lead, 37.2% zink, and 47.6% copper?

My answer is: Alloy A= -195g Alloy B= 637g Alloy C= -117g

I've tried this using the Matrix, and the inverse Matrix, and keep coming up with negitives on some alloys. How can one have negetive alloys?
Thanks for your help.
Neil

Your calculations are correct - the problem is physically inconsistent (however it is consistent numerically).

 

[mmm4444bot]

How can one have negetive alloys?

They can't.

Are you taking a class taught by a machine ?

My experience (so far) with machine-teachers is that they often provide students with errors of both the typographical and logical kind.