Question

a cylindrical pipe has inner diameter 4cm and water flows through it at the rate of 20 meter per minute how long would it take to fill a conical tank of radius 40cm and deepth 72

Answer 1

Radius of pipe = 2 cm
Rate of water flow = 20 m/min = 2000 cm/min
Volume of water flowing in pipe in 1 min. = π * 2 * 2 * 2000 cm3  

Radius of base of conical tank = 40 cm
Depth of tank = 72 cm
Volume of tank = 1/3(π * 40 * 40 * 72) cm3  

Time taken to fill the tank = (π * 40 * 40 * 72)/(π * 2 * 2 * 2000 * 3)
                                              = 24/5 =4.8 minutes = 4 min + .8*60 secs
                                              = 4 minutes and 48 seconds

Answer 2

Radius of pipe = 2 cm
Rate of water flow = 20 m/min = 2000 cm/min
Volume of water flowing in pipe in 1 min. = π * 2 * 2 * 2000 cm3  

Radius of base of conical tank = 40 cm
Depth of tank = 72 cm
Volume of tank = 1/3(π * 40 * 40 * 72) cm3  

Time taken to fill the tank = (π * 40 * 40 * 72)/(π * 2 * 2 * 2000 * 3)
                                              = 24/5 =4.8 minutes = 4 min + .8*60 secs
                                              = 4 minutes and 48 seconds