solutia 1 : ms1 = 400g c1= 20% md1 = 80g
solutia 2 : ms2 = 150g c2= 50% md2 = 75g
apa : ms3 = 300g c3 = 0% md3 = 0 g
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ms = ms1 + ms2 + ms3 = 850g
md = md1 + md2 + md3 = 155g
c = 155·100/850 = 18,235%