What is the inductance of a circuit with a 20-millihenry inductor connected in series with a 50-millihenry inductor?

When inductors are connected in series, their total inductance simply adds together. This behaves exactly like connecting resistors in series. To find the total inductance of this circuit, you just add the individual values: 20 millihenries + 50 millihenries = 70 millihenries. The 14.3 millihenry distractor is the result you would get if you incorrectly applied the parallel formula. The 1,000 millihenry option comes from mistakenly multiplying the two values instead of adding them.