Problem Solving (PS) | Re: There are 2 bars of copper-nickel alloy. One bar has 2 parts

Hi, can anyone explain why is this approach wrong?

I tried to nullify the effects of denominators by making them all equal. Instead of taking ratios as 2/5, 3/5 and then 5/11 as given; I converted all of them to common denominators giving 22/55, 33/55 and 25/55.

Next...since working only with Numerators... I have 22 and 33 on the ends and 25 as their weighted average. So, my ratio will be:

w1/w2 = (33-25)/(25-22) = 8/3

So my ratio of C to N is coming to 8/3.

What's wrong in my approach?

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