When a cylindrical tank is 3/7 full, an inlet pipe with a capacity of 4928 liters per hour fills it completely in 4 hours. If the height of a tank is two times its diameter, then the radius of a tank is:
OPtion
1) 2.8 m
2) 1.9 m
3) 2.1 m
4) 2.4 m
5) 1.4 m
6) 2.0 m
7) 1.8 m
8) 3.5 m
9) 1.2 m
10) None of these
Solution
4/7 volume of a tank = 4928x4 = 19712 liters
.'. Total capacity of tank = (7/4)x19712 = 34496 liters
⇒ Volume of a cylindrical tank = πr²h = 34496 litres = 34496000 cm³
Given, h=2xDiameter=2x(2r)=4r
.'. πr²(4r) = 34496000
(22/7)x4xr³ = 34496000
r³ = 2744000
r = 140 cm = 1.4 m
Correct Option 5)