1. The problem statement, all variables and given/known data https://www.physicsforums.com/attachment.php?attachmentid=20071&stc=1&d=1250025514 The switch in the figure has been closed for a very long time. https://www.physicsforums.com/attachment.php?attachmentid=20071&stc=1&d=1250025514 (a) What is the charge on the capacitor? (b) The switch is opened at t = 0 s. At what time has the charge on the capacitor decreased to 10% of its initial value? 2. Relevant equations E-iR1-iR2=0 emf (delta)Vi=0 Q=Qe^-t/RC (possibly) 3. The attempt at a solution So, I know that the circuit is initially closed, and I don't need current to solve. Also that I probably need to combine resistors because they are in series. Yet, I'm a little confused as how to set up the problem. Any type of help or insight would be deeply appreciated.