Which statement about body water content is true?

Which statement about body water content is true?

• A. The adult body contains about 50 litres of water
• B. The adult body contains about 10 litres of water
• C. The adult body contains about 100 litres of water
• D. The adult body contains about 5 litres of water

Answer: (A)

Water makes up a large portion of the body, and in an average adult total body water is about 50 litres. This aligns with the idea that water is roughly 60% of body weight, though the exact amount varies with age, sex, and body composition. The body’s water is split mainly into two compartments: intracellular fluid inside cells and extracellular fluid outside cells. If total water is around 50 litres, about two-thirds sits inside cells (roughly 33 litres) and about one-third is outside cells (roughly 17 litres). Because of these proportions, 50 litres is a sensible, widely used estimate for an adult. The other figures are far from typical: 10 litres or 5 litres would be far too small for an adult’s total body water, and 100 litres would exceed what the body could plausibly contain given a person’s body weight.

Water makes up a large portion of the body, and in an average adult total body water is about 50 litres. This aligns with the idea that water is roughly 60% of body weight, though the exact amount varies with age, sex, and body composition. The body’s water is split mainly into two compartments: intracellular fluid inside cells and extracellular fluid outside cells. If total water is around 50 litres, about two-thirds sits inside cells (roughly 33 litres) and about one-third is outside cells (roughly 17 litres). Because of these proportions, 50 litres is a sensible, widely used estimate for an adult.

The other figures are far from typical: 10 litres or 5 litres would be far too small for an adult’s total body water, and 100 litres would exceed what the body could plausibly contain given a person’s body weight.