Que 34) 
Is the answer 4.05 m or 405 cm?? 
(Please don't give me similar links; I want exact ans for this). Thank you
34. Water is flowing through a cylinder pipe. Of internal diameter 3 cm into a cylinder tank of base radius 40 cm, at the rate 0.4 m/s . Determine the rise in level of water in the tank in half an hour.