Question

The ratio between the radius of the base and the height of the cylinder is $2:7$, find the radius of the cylinder if its volume is $5632$cu.cm

Answer 1

Let the radius be $2x$ and height be $7x$

Volume$=5632$sq.cm

$\Rightarrow \pi r^{2}h=5632$

$\Rightarrow \frac{22}{7}\times 2x\times 2x\times 7x=5632$

$\Rightarrow 88x^3=5632$

$\Rightarrow x^3=\frac{5632}{88}=64$

$\Rightarrow x^3=4\times 4\times 4$

$\Rightarrow x=4$

Hence radius$=2x=2\times 4=8$cm

Height$=h=7x=7\times 4=28$cm