Mechanics of materials ques / stresses in beams

[macbarbicus]

Homework Statement

refer to attachment

Homework Equations

The Attempt at a Solution

I am completely confused at where to start can someone get me going in the right direction here as to one of the answers.

 

[PhanthomJay]

Hi, Macbarbicus, welcome to PF!

Per forum rules, you are going to have list what you believe are the relevant equations, and show some attempt at your work, before we can be of assistance. You should be familiar with the shear flow formula which indicates how the shear stresses vary over the beam cross section.