R1=r1+r2+r3=40+65+20=125 Oм
1/R2=1/r1 +1/r2 +1/r3=1/40 +1/65 +1/20= 0.09
R2=65/7=9.28 Ом
R1/R2=125/9.28=13.46
R1=r1+r2+r3=40+65+20=125 Oм
1/R2=1/r1 +1/r2 +1/r3=1/40 +1/65 +1/20= 0.09
R2=65/7=9.28 Ом
R1/R2=125/9.28=13.46