Second moment of area about an axis along any diameter in the plane of the cross section (i.e. x-x, y-y) is each equal to (1/4)pi r^4.
The second moment of area about the zz-axis (along the axis of the cylinder) is the sum of the two, namely (1/2)pi r^4.
The derivation is by integration of the following:
int int y^2 dA
over the area of the cross section, and can be found in any book on mechanics of materials.
The fastest way is to just use a scientific calculator.
To do it without a calculator, use prime factorization.
I'll only do the second one which is the answer.
27 x 8
= 3^3 x 2^3 = 6^3
Which is a perfect cube.
I believe the answer is b and e
