Question

A rectangular piece of paper $11$ cm $\times$ $4$ cm is folded without overlapping to make a cylinder of height $4$ cm. What will be volume of the cylinder ?

• A. $36.5$ $c{m}^3$
• B. $38.5$$c{m}^3$
• C. $37.5$ $c{m}^3$
• D. None of these

Answer 1

The correct option is B $38.5$$c{m}^3$

Length of the paper becomes the perimeter of the base of the cylinder and width becomes height.
Let radius of the cylinder = r and height = h
Perimeter of the base of the cylinder = $2\pi r$
= 1
or $2\times \frac{22}{7}\times r=11$
Therefore r = $\frac{7}{4}$ cm
Volume of the cylinder = r
= $\pi r^{2}h$
= $\frac{22}{7}\times \frac{7}{4}\times \frac{7}{4}\times 4c{m}^3$
= 38.5 $c{m}^3$
Hence, the volume of the cylinder is 38.5 $c{m}^3$