Advanced Physics $-$ capacitor

Please kindly show me clear steps and explanation, thanks a lot!

Ex $4$

The circuit allows, with a switch, to switch to c mode of the capacitor or to d mode.

The charging voltage is U$=20$V$.$ The resistors are R$1=20$ and R$2=10.$

The capacity of the capacitor is C$=20$ muF; the latter is initially completely discharged.

$($note: no differential equation here$)$

We start with the switch in charge mode.

a$)$ determine the maximum current traveled in the circuit; when does it take place?

b$)$ determine the maximum charge contained in this capacitor.

c$)$ what is the current in the circuit when the capacitor charge is at half its maximum charge?

d$)$ what is the maximum energy contained in the capacitor when it is full?

We now switch the switch to discharge mode. The capacitor is initially full.

e$)$ What is the current in the circuit when the charge on the capacitor is only half its maximum charge?

f$)$ if the time necessary to go from a full charge to half charge is $0\mathrm{.}3$ ms $,$ estimate the average discharge power