Answer
$ 1.25\times 10^4\;\rm N\cdot m $
Work Step by Step
To find the torque around bolted point, which is on the right side in the figure below, we need to find the forces exerted on the beam and their distance to this point.
$$\sum \tau=F_n(0)+Mg(2)+mg(4)=2Mg+4mg$$
where $M$ is the mass of the steel beam and $m$ is the mass of the worker.
$$\sum \tau= 2g(M +2m)$$
We chose counterclockwise to be the positive direction, hence the positive signs above signs.
Plugging the known;
$$\sum \tau= 2\times 9.8(500 +[2\times 70])$$
$$\sum \tau=\color{red}{\bf 1.25\times 10^4}\;\rm N\cdot m $$
