I got this question and so far I think I have worked out the tension correctly.
2T = 5g + 4g
T= 4.5g
However I don't know how to proceed with the second part where it is asking the force exerted on B by ground. I think this would be the reaction force they are asking for? Any help would be appreciated
For P you would be having T=4g and for B you would have N+T=5g. Solving For N and T you would find N=1g and T=4g(trivially from first eqn.). Here N=Normal force by ground.