How to find current in this circuit passing through 4ohm resistor
Try to redraw it this way next time: 









simulate this circuit &ndash; Schematic created using CircuitLab

Notice how I mark the same node with different colors to see what is connected to what. 

Also, notice that we can skip the left \$ 12\Omega\$ resistor (R1) because it is connected directly across the voltage source

So we are left with this: 







simulate this circuit