It looks like you're describing a circuit with resistors $R_1 = 5 \, \Omega$, $R_3 = 10 \, \Omega$, and another resistor $R_3 = 15 \, \Omega$. Additionally, you're giving a voltage of $V_3 = 20 \, V$, but I need to clarify whether you're describing a series or parallel circuit, or if the resistors are in different branches.

If the resistors are arranged in series or parallel, the current will be calculated differently. Here are a couple of approaches:

1. If the resistors are in series, the total resistance is the sum of individual resistances, and the total current is given by: $I = \frac{V}{R_{\text{total}}}$ where $R_{\text{total}} = R_1 + R_3 + R_3$.

2. If the resistors are in parallel, the total resistance is calculated as: $\frac{1}{R_{\text{total}}} = \frac{1}{R_1} + \frac{1}{R_3} + \frac{1}{R_3}$ and then the current is: $I = \frac{V}{R_{\text{total}}}$

Please clarify the type of connection for the resistors (series or parallel), or if it's something else.