Direction: Read the table given below carefully and answer the following…

Direction: Read the table given below carefully and answer the following question.
The data shows the volume and height of 4 right circular (cylindrical) tanks P, Q, R and S. The data also depicts the time taken to fill or empty each tank by inlet pipes A and B and outlet pipe C.
1. The ratio between the time taken by pipe B and that taken by pipe C is different for different tanks because the operator used the pipes in different ways.
2. The radius of tank S is 10.5 m.

In tank R (starting from empty), pipe A was opened for 9 hours and then closed. Pipes B and C were then opened together for 3 hours and then both were closed. After a total of 12 hours, approximately what volume of the tank remained empty (in cubic metres)? (Note: pipes A and C together keep the tank at the same level, i.e. outlet C empties at exactly the rate at which inlet A fills.)