What is the total resistance of the circuit with a 20 ohm and 30 ohm resistance

For series connection:

Total resistance is 50 ohms

For parallel connection:

Total resistance is 12 ohms

Explanation:

for series connection:

Total resistance=20+30=50 ohms

For parallel connection:

Let R be total resistance

1/R=1/30 + 1/20

1/R = (2+3) / 60

1/R=5/60

1/R=1/12

Cross multiply

1x12=1xR

12=R

R=12 ohms