Question

Find the equivalent resistance of this circuit.​

Answer 1

`(R_1 +R_2)||R_3\\\\R_(eq) = \left(\frac 1{R_1 + R_2} + \frac 1{R_3}} \right)^(-1)\\\\\\~~~~~~=\left( (1)/(100+200) + \frac 1{600} \right)^(-1)\\\\\\~~~~~~=\left( (1)/(300) + (1)/(600) \right)^(-1)\\\\\\~~~~~~=\left((3)/(600) \right)^(-1)\\\\\\~~~~~~=\frac{600}3 \\\\\\~~~~~~= 200~ \Omega`