If all the batteries are ideal then potential at junction C is :

Key word in the question is ‘Ideal bettery’ that means no internal resistance.
Now use KCL at the junctions for which sum of the current at the junction to be zero.
Since Va = 50 V, which is at higher vpotential, so you can take the current through this branch will be redistributed in to others.
so calculate the current
Iac = Icb + Icd
Va – Vc /R = Vc – Vb /2 + Vc – Vd /3

I hope you can solve now the rest questions...

Good Luck..........................................................