tolong dibantu......

a. R seri atas = 20+20+20= 60 ohm
R seri bawah = 15+15=30 ohm
R paralel = 1/Rp = 1/60+1/30=3/60
Rp =60/3 = 20 ohm (r pengganti)

b. I=V/R =6/20 =3/10 = 0,3 A