Physics - NLM Question with Solution | TestHub

Let the rope tension be $T$. The man pulls the rope with force $T$; the rope pulls him up by $T$ as well. Taking the man and plank together as the system: the lower movable pulley is supported by $2T$, and the rope segments holding the system total $4T$ upward in all (as in the figure).

Equilibrium: $4T=60\mathrm{kgf}\Rightarrow T=15\mathrm{kgf}$.