1. The problem statement, all variables and given/known data Find the time constant in the following circuit when switch K1 is open. R1 = 100 Ohms R2 = 200 Ohms C1 = 6 micro Farads E1 = 9V 2. Relevant equations T = RC 3. The attempt at a solution When the resistors are in series or parallel, I am clear on how to do this, however when the capacitor is discharging, I don't think the resistors are in series or parallel, so I don't know how to find the equivalent resistance.