A water tank is formed with the combination of

cylinder and hemisphere. The total height of the

tank is 20 m and base area is 616 m². If the tank is

filled with water at the rate of 45 paisa per liter,

what is the total cost to fill the water? Find it.

421160 Rupees

Step-by-step explanation:

Base area of cylinder = π * r^2

=> 616 = 22/7 * r^2

r^2 = (616 * 7) : 22

= 4312 : 22

= 196

Therefore r = √196

= 14 m

Total height of the tank = 20 m

Therefore height of cylinder

= 20 - 14

= 6 m

Volume of water tank

= Volume of cylinder + Volume of hemisphere

= π * r^2 * h + 2/3 * π * r^3

= 22/7 * 14 * 14 * 6 + 2/3 * 22/7 * 14

* 14 * 14

= 22/7 * 14 * 14 (6 + 2/3 * 14)

= 616 (15.3)

= 9424.8 m^3

= 9424800 l

(to convert m^3 to litre, multiply volume value by 1000)

Total cost to fill water

= 9424800 * 45

= 424116000 paise

= 4241160 Rupees