How to calculate the voltage of these capacitors?
Write out the mesh equations for the circuit using KCL.  And remember that I = C * dv/dt for current flowing through each capacitor.  

The result should be a third order differential equation.

The voltages a,b,c can be found by solving the third order differential equation.

The result in the time domain should look like the a sum of decaying exponentials.

You can double check your answer by making sure that at infinite time the result looks like the circuit solution with all capacitors open.