**Question:** In an adult man weighing 70 Kgs, the Total body water volume will be about -

A. 20 liters
B. 25 liters
C. 50 liters
D. 60 liters

**Correct Answer:** .

**Core Concept:**
Total body water (TBW) is a measure of the volume of water contained within the body. In adults, TBW constitutes approximately 55-60% of total body weight (TBW % = (TBW / TBW) x 100. In this case, we are dealing with an adult male weighing 70 kg.

**Why the Correct Answer is Right:**
The correct answer is derived from the formula for calculating total body water percentage: TBW % = (TBW / TBW) x 100. In this scenario, the total body weight (TBW) is 70 kg. Plugging this value into the formula gives us:

TBW % = (70 kg / 70 kg) x 100 = 100%

Since the percentage is 100%, it means that the total body water volume (TBW) is equal to the total body weight (TBW), which is 70 liters.

**Why Each Wrong Option is Incorrect:**
A. 20 liters: This choice is incorrect because it does not correspond to the correct percentage (100%) calculated above.
B. 25 liters: This choice is incorrect as it is less than the calculated TBW (70 liters).
C. 50 liters: This choice is incorrect because it is half of the calculated TBW (70 liters).
D. 60 liters: This choice is incorrect as it is less than the calculated TBW (70 liters).

**Clinical Pearl:**
Understanding the calculation of TBW percentage is important for assessing hydration status and fluid balance in patients. For example, in cases of dehydration, the TBW percentage typically decreases, while in cases of fluid overload, it increases. Monitoring TBW can help guide fluid therapy and monitor the patient's fluid balance.