tentukan hambatan subtitusi, hambatan penggantinya, kuat arus I1 dan I2 bantu jawab ya, makasih

3. a. 1/rp=1/6+1/12+1/18=6/36+3/36+2/36=11/36
rp=36/11
b.rs=8+4=12
rs=16+8=24
rp=12×24/12+24=8
rs=8+12=20
4.rp=6×12/6+12=4
I1=V/R
=24/6
=4
I2=V/R
=24/12
=2