Boy on spring board - Moments Question using Simultaneous Equations

Note: Non-uniform plank means the CG of the plank is not at its centre

a) Find the weight of the boy.

b) How far is the centre of gravity of the plank from point A?

Solutions:

a) 300 N and b) 6.67 m

Click on the video tutorial if you can’t derive the 2 equations.