How do you make an ideal circuit?
I am not going to ans but give you hints to solve.


Observe the direction of 8A current source and ib. 
Observe Vg source and 8A source, how they are connected in and its polarity. 
Also the current dependent sorce (ib/4) wrt to Vg.
Calculate power using Power = V*I equation.


Hope this will help.