sol 1
md = 200 g
ms = md + m. apa = 200 +1000 = 1200 g
c% = md x 100 / ms = 200 x 100 / 1200 => c% = 16,67% sol 2
md final = md1 + 200 = 200 + 200 = 400 g
ms.final = ms1 + 200= 1200 + 200 = 1400 g
=> c% = md final x 100 / ms final = 400 x 100 / 1400 => c% = 28,57%