Answer:
a. Ratio of their circumference = 2:3
b. The ratio of their surface areas = 2:3
c. The ratio of their volume = 4:9
Step-by-step explanation:
Let the cylinders be labelled as A and B respectively.
Diameter of cylinder A = 6 in,
its radius =
=
= 3 in
Diameter of cylinder B = 9 in,
its radius =
=
= 4.5 in
Thus,
a. circumference of a circle = 2
r
Circumference of cylinder A = 2
r
= 2 x
x 3
= 6
in
Circumference of cylinder B = 2
r
= 2 x
x 4.5
= 9
Ratio of their circumference = 
= 
= 2:3
b. The surface area of a cylinder = 2
rh
the surface area of cylinder A = 2
rh
= 6
h
the surface area of cylinder B = 2
rh
= 9
h
The ratio of their surface areas = 
= 
= 2:3
c. Volume of a cylinder = 
h
volume of cylinder A = 
h
=
x
x h
= 9
h
volume of cylinder b = 
h
=
x
x h
= 20.25
h
The ratio of their volume = 
= 
= 4:9