Try this solution:
rule: the volume of any cylinder can be calculated with formula: V=πr²h, where r - the radius of the base, h - height of the cylinder.
Using the formula written above:
5. V=π*25*6=150*3.1415≈471.2389≈471.2 cm³;
6. V=π*64*4=256*3.1415≈804.2477≈804.3 cm³