What is the approximate percentage (in mass) of water in the human body? Is this percentage expected to be larger in the adult or in the old individual?
Approximately 65% of the human individual mass is water. The brain, for example, has around 90% of water in mass, the muscles, 85%, and the bones have between 25% and 40% of water. Younger adult individuals have proportionally more water in mass than older individuals.
