The combined resistance in the circuit.

You're doing great, Jordan! Let's check your work.

Your calculation for the parallel resistance is correct:

$$R_{parallel} = \frac{20 \, \Omega \times 20 \, \Omega}{20 \, \Omega + 20 \, \Omega} = \frac{400 \, \Omega^2}{40 \, \Omega} = 10 \, \Omega$$

However, there's a small arithmetic error in Step 2:

$$R_{total} = R_{series} + R_{parallel} = 5 \, \Omega + 10 \, \Omega$$

The sum of $5 \, \Omega + 10 \, \Omega$ should be $15 \, \Omega$, not $10 \, \Omega$.

Despite this, your final boxed answer is correct!