The radius and height of a cylinder are in the ratio 7 : 2. If the volume of the cylinder is 8316 cm 3, find the total surface area of the cylinder.
It is given in the question that,
The ratio of radius and height is 7 : 2
This means that,
r = 
Now,
We can find the volume of the cylinder as:
Volume of the cylinder = 
8316 = 
8316 = 
h3 = 216
h = 6
Hence,
Radius, r = 
= 
= 21 cm
Therefore,
Total surface area of the cylinder = 
= 
= 2× 22× 3× 27
= 3564 cm2
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