r1=20ohm R2=15ohm dan R3=30ohm besar arus 1 dan tegangan total

Hambatan rangkaian 
R = 20 + (1/15 + 1/30)^-1 = 30 ohm

V3 = V2, karena paralel 
i3 R3 = i2 R2
i3 • 30 = 2 • 15
i3 = 1 A

I = i2 + i3
I = 2 + 1 = 3 A ← jwb

V = I R
V = 3 • 30 = 90 V