C=mdx100/ ms, unde ms=md+m,apa
md= cxms/100
c1= 25x100/ (25+275)= 8,33%
c2=25x100/(300+25)=---------------------------
c3=(25+25)x100/ (300+25)=---------------------
c4= ( c1md1+cxmd)/(ms1+ms)=>(0,0833x300+0,2x200)/(300+200)------------
c5=25x100/ (300-50)=-------------------------
calculeaza c2,c3,c4,c5 !!!!