Question

Given only a 30 Ohm and one 50 Ohm resister, list all possible values of resistance that can be obtained.

Answer 1

You can connect them in two ways: in serial and parallel connection.
For serial: R_ser =R₁ + R₂ = 30 + 50 = 80 [Ohm]
For parallel: R_par = (R₁R₂)/(R₁ + R₂) = 18.75 [Ohm]
If only one resister is included into the chain, R₁ = 30 [Ohm] and R₂ = 50 [Ohm]