ms1= 20 g , w1= 25%
ms2 = 10 g , w2= 5%
-----------------------------/----
w.f.= ?%
------------------------------//----
stim ca w%= mdx100/ms
=> md1 = ms1xw1/100 = 20x25/100 = 5 g
=> md2 = ms2xw2/100 = 10x5/100 = 0,5 g
=> md.final = md1 + md2 = 5,5 g
ms.final = ms1 + ms2 = 30 g
=> w.f. = md.finalx100/ms.final
= 5,5x100/30 = 18,33%