Question

The radius of the cylinder is half its height and area of the inner part is 616 sq. cms. How many litres of milk approximately, can it contain?

• A. 1.4 L
• B. 1.5 L
• C. 1.7 L
• D. 1.9 L

Answer 1

The correct option is B 1.5 L

Given that r=$\frac{1}{h}$ And
$2\Pi rh+\Pi r^2=616m^2$
$\therefore 2\Pi \left(\frac{1}{2}h\right)h+\Pi (\frac{1}{2}h{)}^2=616m^2$
$\Rightarrow \frac{5}{4}\times \frac{22}{7}{h}^2=616\Rightarrow (616\times \frac{28}{110})=\frac{28\times 28}{5}$
$\therefore Volume=\Pi r^{2}h=\frac{22}{7}\times \frac{1}{4}{h}^2\times h$
$\therefore Volume=\frac{22}{7}\times \frac{1}{4}\times \frac{28\times 28}{5}\times \frac{28}{\sqrt{5}}$
$\therefore Volume=\frac{22\times 28\times 28}{25}\times \sqrt{5}=\frac{22\times 28\times 28\times 223}{25\times 100}=1.53$liter