Max compressive axial force in a bar in a truss

[cmoloney90]

I've attached the question. I'm not looking for solution just general guidance on how to tackle the question. Do I calculate the internal forces? Where do I put the live load, at node 3 or the midspan of 2 and 3?

 

[PhanthomJay]

After breaking up the uniform load into point loads applied at the lower joints, try placing the live load at node 2, then at node 3, to see which yields the greater internal force in 7-8.