Exercise 2 solution

The round turn and two half hitches should hang the weight securely. The round turn takes most of the strain, so the half hitches are not squeezed hard and the knot is usually easy to untie afterwards.
A clove hitch under the same load often tightens and grips harder, and can be more awkward to release, while also being more likely to slip if the load swings.
Takeaway: the round turn carries the load; the hitches only lock it.