7) RA=20/100=0,2
RB=100/2500=0,04
RT=0.2+30+0.04= 30,24
8) RA=100/32000=0,003125
RB=160/6400=0,025
RT=20+0.003125+0.025+50=70,028125
9) RA=100/1600=0,0625
RB=100/2400=0,0416
RC=180/216000=0.00083
RT=0,0625+0,0416+0,00083+60=60,105
10) RA=80+40=120
RB=200/9600=0,02083
RC=100/2400=0,0416
RD=220/384000=0,000572916
RT=40+0,02083+4+0,0416+100+0,000572916=144,06