Sewerage system is usually designed for A. 10 years B. 25 years C. 50 years D. 75 years

The correct answer is C. 50 years.

Sewerage systems are designed to last for at least 50 years. This is because they are critical infrastructure that must be able to withstand a variety of stresses, including heavy rains, flooding, and earthquakes. In addition, sewerage systems must be able to handle the increasing demands of a growing population.

There are a number of factors that can affect the lifespan of a sewerage system. These include the type of materials used, the quality of construction, and the level of maintenance. However, with proper care and maintenance, a sewerage system can last for many years.

Here is a brief explanation of each option:

• Option A: 10 years. This is the shortest possible lifespan for a sewerage system. It is unlikely that a sewerage system would be designed to last for only 10 years, as this would not be cost-effective.
• Option B: 25 years. This is a more realistic lifespan for a sewerage system. However, it is important to note that the lifespan of a sewerage system can vary depending on a number of factors.
• Option C: 50 years. This is the most common lifespan for a sewerage system. It is designed to last for at least 50 years, and can often last for much longer with proper care and maintenance.
• Option D: 75 years. This is a very long lifespan for a sewerage system. It is unlikely that a sewerage system would be designed to last for 75 years, as this would be very expensive.