Question

two cylinders have their radii 4:5 and their height is 5:6 find the ratio of their curved surface
pls do it ​

Answer 1

radius= 4x

height=5y

Curved surface area = 2*pi*r*h

=2*pi*4x*5y

Case 2

radius=5x

height=6y

Curved surface area = 2*pi*5x*6y

Case1/Case2 = 2*pi*4x*5y/2*pi*5x*6y

( simplification = cancel 2 to 2 and pi to pi and x to x and y to y)

=4*5/5*6

20/30 ( simplification )

2: 3

Answer 2

r

1

:r

2

=4:5

h

1

:h

2

=5:6

∴V

1

:V

2

=π×4×5:π×5

2

×6 (V=πr

2

h)

=π×16×5π×25×6

=80π:150π

=8:15