Question

Sonali cut a rectangular sheet of paper for her Mathematics project.She cut the sheet whose length and breadth are in the ratio 4:3 and perimeter was 42 cm.She saw that sheet was little smaller.She increased both length and breadth by 2 cm which was of proper size.​

Answer 1

Answer:

Let V

1

and V

2

be the volumes of two cylinders. When the sheet is folded along its length, it forms a cylinder of height h

1

=18cm and perimeter of base equal to 30cm. Let r

1

be the radius of the base. Then,

2πr

1

=30⇒r

1

=

π

15

∴V

1

=πr

2 h 1

=π× π 2

225 ×18cm

3 = π

225 ×18cm 3

Similarly, V 2

=πr

22 h

2 =π×(π 92 ) ×30cm

3 = π 81×30

3cm

∴ V2 V 1

= 81×30

225×18

= 35

.