(a) Two balls, one of iron and the other of aluminium experience the same upthrust when dipped completely in water if both have equal volumes.
(b) An empty tin container with it’s mouth closed has an average density equal to that of a liquid. The container is taken 2m below the surface of that liquid and is left there. Then the container will remain at the same position.
(c) A piece of wood is held under water. The upthrust on it will be more than the weight of the wood piece.