Solving a Circuit

This is an example of a Series-Parallel circuit.

How I solve it?

1. I always check the circuit first, if it is a Series, Parallel, or Series-Parallel Circuit.
2. Then I'll find the formula for the specific circuit and write down what is missing in the circuit.
3. The total voltage, resistance for each resistor, or the current is always given in the circuit. You will usually need to find the voltage passing through the circuit, total resistance, total current, current passing through each resistor, and Power
4. Remember that different circuit has always different formula and the Series-Parallel is a combination of the two circuit.

Here's a link for the formula about the circuits.