Answer:
D/t>20
Explanation:
Lets take
D =Diameter of thin cylinder
t =Thickness of thin cylinder
So a cylinder is called thin cylinder if the ratio of diameter to the thickness is greater than 20 (D/t>20 ).
But on the other hand a cylinder is called thick cylinder is ratio of thickness to the diameter is greater than 20 (t/D>20 ).
So the governing ratio of thin walled cylinder is 20.
