In a circuit, two resistors of 100 Ω and 80 Ω are connected in parallel. The parallel group is then connected in series with a 100 Ω resistor. What's the total resistance of the circuit?

Answer:Total Resistance = [tex]\frac{1300}{9}[/tex] Ω  (or 144.44 Ω)Step-by-step explanation:If two resistors, with resistance x and y, are connected in parallel, their total resistance is given by the formula:[tex]\frac{1}{Total}=\frac{1}{x}+\frac{1}{y}[/tex]If 2 resistors with resistance x and y and connected in series, their total resistance would be:Total = x + yNow, the first part, 100 and 80 are in parallel, so according to formula it would be:[tex]\frac{1}{Total}=\frac{1}{x}+\frac{1}{y}\\\frac{1}{Total}=\frac{1}{100}+\frac{1}{80}\\\frac{1}{Total}=\frac{9}{400}\\Total = \frac{400}{9}[/tex]Now, this is connected in series with 100, so the grand total would be:Total Resistance of Circuit = [tex]\frac{400}{9}+100=\frac{1300}{9}[/tex]This is the total resistance of the circuit.