An outlet pipe in the roof with length 13 m. and breadth 11 m. was closed at the time of rain fall. After rain fall, it was seen that water having logged in the roof with 7 cm. depth. The length of diameter of outlet pipe is 7 cm. and water comes our cylindrically with 200 m. length/min. Calculate the time required is drainout whole amount of water after opening the pipe.