Daily loss of water through breathing, perspiration and excretion is

Options

A. 1.5 litres
B. 3 litres
C. 5 litres
D. 7.5 litres.

Answer

To solve the question regarding the daily loss of water through breathing, perspiration, and excretion, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding Water Loss through Breathing**:
- When we breathe, we exhale not only carbon dioxide but also water vapor.
- It is estimated that the lungs expel approximately 1.5 liters of water vapor daily through respiration.

2. **Calculating Water Loss through Perspiration**:
- Perspiration, or sweating, is another significant way the body loses water.
- On average, the body loses about 0.5 to 1 liter of water per day through sweat, depending on factors like temperature and physical activity. For our calculation, we can take an average of 0.5 liters.

3. **Water Loss through Excretion (Urine)**:
- The kidneys filter blood to produce urine, which is another route for water loss.
- The daily output of urine is typically around 1 to 1.5 liters. For our calculation, we can take an average of 1.5 liters.

4. **Total Daily Water Loss Calculation**:
- Now, we can sum up the water loss from all three processes:
- Water loss through breathing: 1.5 liters
- Water loss through perspiration: 0.5 liters
- Water loss through excretion: 1.5 liters
- Total water loss = 1.5 liters (breathing) + 0.5 liters (perspiration) + 1.5 liters (excretion) = 3.5 liters.

5. **Conclusion**:
- Therefore, the total daily loss of water through breathing, perspiration, and excretion is approximately 3.5 liters.

### Final Answer:
The daily loss of water through breathing, perspiration, and excretion is approximately **3.5 liters**.

---