Question

A rectangular sheet of paper 22 cm long and 12 cm broad can be curved to form the lateral surface of a right circular cylinder in two ways. Taking $\pi =\frac{22}{7}$, the difference between the volumes of the two cylinders thus formed is

• A. 200 c.c.
• B. 210 c.c.
• C. 250 c.c.
• D. 252 c.c.

Answer 1

Answer: (B)

210 c.c.

Difference between the volumes of the two cylinders
$=[\pi r_1^2{h}_1-\pi r_2^2{h}^2]$
$=\pi [{\left(\frac{7}{2}\right)}^2\times 12-{\left(\frac{21}{11}\right)}^2\times 22]$
$=\frac{22}{7}\times 7\times 7\times 3[1-\frac{3\times 2}{11}]=210c.c.$