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

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

In tank R, pipe A was opened for 9 hours and then closed. Pipe B and C were the opened together for 3 hours and then both pipes were closed. After a total of 12 hours, approximately what volume of tank remained empty (in cubic meters), if both pipes A and C were opened together, tank will always be empty).