Question 181264
The given height of 7cm makes no sense, I changed the height to 70 cm.
:
The total surface area of a hollow cylinder, which is open from both sides, is 4620cm2. Area of base ring is 115.5cm2, and height is 70 cm.
 Find the thickness of the cylinder
:
I assume the "total surface area" is the surfaces of both the inside and 
the outside of the cylinder,
:
Surface area of just the outside: 4620/2 = 2310 sq/cm
:
Surface area = circumference * height
:
Find the circumference: 2310/70 = 33 cm
:
Find the diameter:
 d*pi = 33;
 d = 33/pi;
 d = 10.5 cm diameter of the cylinder
:
Find the diameter of the base
pi*r^2 = 115.5
r^2 = {{{115.5/pi}}}
r^2 = 36.6
r = {{{sqrt(36.6)}}}
r = 6.05 cm
d = 12.1 cm diameter of the  base
:
12.1 - 10.5 = 1.6 cm
:
Thickness = {{{1.6/2}}} = .8 cm
;
:
Let me know if I assumed right here.  Carl