Question

A 16 cm x 9 cm paper rectangle can be curled to form a cylinder in two ways (by bringing the oppo
edges in contact). Then the ratio of the volumes of the two cylinders is :
(A) 9:16
(B) 16:25
(C) 81 : 256
(D) 3:4.
[Proficiency Test 2011]​

Answer 1

Answer:

A

Step-by-step explanation:

Two Cases:

1st case:

when

2πR = 9

R = 9/2π

and H = 16

then

volume = πR^2H

=$\pi \times {(9 \div 2\pi)}^{2} \times 16$

...............(1)

2nd case

when

2πR = 16

R = 16/2π

and H = 9

then

volume = πR^2H

=

$\pi \times {(16 \div 2\pi)}^{2} \times 9$

...............(2)

now the answer is

(1)/(2)

= 9/16