# Realizing 2 Resistors are in series in an RC circuit

I understand that when the switch is open, the capacitor acts like an open circuit & therefore the current in the capacitor branch would be equal to 0. When I solved the circuit using nodal analysis, I realized that the 2k ohm and the 4k ohm are in series.

How would I look at the circuit and automatically realize they're in series? Because realizing they're in series would result in a much easier answer using KVL. 5(-10) + Vc - 4(6/6) = 0

By the way, the current through the capacitor is zero not because the switch is open; it is zero because the circuit is effectively a dc circuit because the switch has not changed position for an infinite amount of time before $$\t=0\$$. This is a mathematically convenient assumption but it is also a reasonable approximation to many real-life situations.