mixing 5.25% allow with 2.84% allow to get 4.15% alloy

[Marina]

Please please please help - I am completely lost - what do I do here? I don't even know where to start here...

Steel is an alloy of iron and nickel. A steel recycling company has two piles of scrap steel. Pile A contains steel with 5.25% nickle content. Pile B contains steel with 2.84% nickel. The company has an order for 32.5 tonnes of steel containing 4.15% nickle. How mach scrap steel should be taken from each pile for reprocessing?

Thanks.

 

[arthur ohlsten]

Re: Homework help needed

let A = the amount of type A used
let B= the amount of type B used

eq 1) A+B=32.5

eq 2) B[2.84]+A[5.25]=[A+B][4.15]
replace B with 32.5-A in eq 2

[32.5-A][2.84]+5.25A=[A+32-5-A][4.15
[32.5][2.84]+2.41A=32.5[4.15]
2.41A=32.5 [4.15- 2.84]
A= 32.5[1.31] / 2.41 Answer

thn B is obvious

please check math
Arthur

 

[Marina]

Re: Homework help needed

Thank you so-so much, Arthur!

Now it looks so simple now... after you''d done it.

Thanks, again
Marina

 

[arthur ohlsten]

Re: Homework help needed

Marina-
You are welcome

I suggest you now do it yourself solving the two equations differently than I did. if you do that you will then remember the approach and "own" the method used
Arthur

 

[mmm4444bot]

Re:

Now it looks so simple now... after you''d done it.

This goes without saying because it is generally true.

~ Mark :|