Question

62. The radii of two cylinders are in the ratio of
1:2 and heights are in ratio of 2:5. The ratio
of their volume will be
(a) 1:10
(b) 1:8
(c) 1:5
(d) 2:9​

Answer 1

Answer:

option a) is the correct answer

Hopes this helps you ☺️

Answer 2

Answer:

(a) 1:10

Step-by-step explanation:

Let,

The radius of the first circle be = x units (r)

and height of the first circle be = 2x units (h)

The radius of second circle be = 2x units (R)

and height of second circle be = 5x units (H)

As we know that

Volume of circle = π×r²×h cubic units

For ratio between their volumes

Volume of first circle ÷ Volume of second circle

= π × r²× h ÷ π× R² × H

= π × (x)² × 2x ÷ π × (2x)² × 5x

= π × (x)² × 2x ÷ π × 4x² × 5x

= 2x³ ÷ 20x³ [cancelling out π from π]

= 2 ÷ 20 [cancelling out x³ from x³]

= 1 ÷ 10

Therefore the ratio between their volumes = 1:10