Question

70 cylindrical pillars each of radius 10 cm and height 20 m would require $m^3$ of concrete.

• A. 4.4
• B. 44
• C. 0.44

Answer 1

The correct option is B 44

It is given that r = $\frac{10}{100}$ m and h = 20 m.
Volume of cylinder = $\pi r^{2}h$.
Volume of concrete required for 1 pillar
= $\frac{22}{7}\times \frac{10}{100}\times \frac{10}{100}\times 20$
Volume of concrete required for 70 such pillars
= $70\times \frac{22}{7}\times \frac{10}{100}\times \frac{10}{100}\times 20$
$=44m^3$