Without the diagram, it is not clear at what angle the cable makes with the vertical.
Draw the free diagram.
The hinge at the wall means that there will be a horizontal and a vertical force to achieve equilibrium, meaning
The "uniform beam" means that the weight is distributed uniformly along the beam, or its centre of mass is at mid-length.
You will have three unknowns, namely Rx and Ry at the hinge, and T for the tension of the cable.
Set-up the 3 equilibrium equations and solve for the unknowns, and hence the solution to (b) and (c).