Two resistances of 5-0 Ω and 7-0 Ω are connected in series and the combi- nation is connected in parallel with a resistance of 36-0 Ω. The equivalent resistance of the combination of three resistors is

Correct option is C

To calculate the equivalent resistance, follow these steps: Step 1: Calculate the total resistance of the two resistors in series Resistors in series add directly: R_series = R1 + R2 R_series = 5.0 Ω + 7.0 Ω = 12.0 Ω Step 2: Combine the series resistance with the parallel resistor The formula for equivalent resistance of two resistors in parallel is: 1/Req = 1/R_series + 1/R3 Here, R_series = 12.0 Ω and R3 = 36.0 Ω. Substituting these values: 1/Req = 1/12.0 + 1/36.0 Step 3: Simplify the fractions 1/Req = 3/36.0 + 1/36.0 = 4/36.0 1/Req = 1/9.0 Step 4: Calculate the equivalent resistance Req = 9.0 Ω Final Answer: The equivalent resistance of the combination is: (c) 9.0 Ω