Question

A circuit includes a 220 resistor connected in series with two parallel resistors with values of 120 and 300. Whats the total circuit resistance?

Answer 1

For parallel resistors:
$\frac{1}{r } = \frac{1}{120} + \frac{1}{300}$
equivalent resistance: 85.7 ohms

for total circuit:
85.7 + 220 = 305.7ohms