A 6 Ω and a 12 Ω resistor are connected in parallel. This combination in turn is connected in series with a 4 Ω resistor. What is the equivalent resistance of this combination?

Answer 1

The reciprocal addition rule should be used which is 1/R1+1/R2=1/Rtotal. So since the two resistors are in parallel, their equivalent value is 4Ω. This value is then in series with another resistor with a 4Ω resistance. Resistance adds in series, so the overall equivalent resistance should be 8Ω.