solutia 1 : ms; c; md1 = c·ms/100
solutia 2 : ms 2c md2 = 2cms/100
solutia 3 : ms ; 3c md3 = 3cms/100
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solutia finala : 3ms md = md1 + md2 + md3 = 6·c·ms /100 cf = 30%
(6·c·ms/100)·100/(3ms) = 30 2c = 30 c = 15% (solutia 1)
2c = 30% (solutia 2) 3c = 45% (solutia 3)