The pillars of an apartment are in a cylindrical shape. If each pillar has a circular base of radius 40 cm and height 20 m, then how much concrete would be required to build 7 such pillars?
70.4
Radius of base of cylinder = 40 cm
Height of cylinder = 20m = 2000 cm
Volume of single cylinder =πr2h=227×40×40×2000
=704000007 cm3
Converting cm3 to m3
1cm=10−2 m
1 cm3=10−6 m3
∴70400000 cm3=70.4 m3
=704000007 cm3 =70.47 m3
Thus, volume of 7 such pillars = Volume of one such pillar x 7 =70.47×7=70.4 m3