Question

Give me way to answer it I am bit confused about it.

Answer 1

Diameter of pipe = 20 mm

hence Radius = 10 mm = 0.1 cm

Since, water is flowing at rate of 10m per minute

Hence, Height of cylindrical pipe in 1 min, h = 10 m = 1000 cm

So, Volume of water which flows in 1 min = πr^h

                                                                    = 3.14*0.1*0.1*1000

                                                                    = 31.4 cm^3

Volume of Conical Vessel = πr^2h/3 = 10053.1 cm^3

Hence,time taken =

Volume of Conical vessel/Volume of water flowing in 1 min        

                 = 10053.1/31.4 ≅ 320 mins = 5 hours 20 mins