We have the fomular:

So try inserting your values and you should get the result.
19.75 divided by 3.25 = m
M= 6.07692307692
Hope this helps :D
Answer:
nine to the one third power all raised to the third power equals nine raised to the one third times three power equals nine
Volume of a cylinder = πr² * l
V = 12²π * 20
V = 144π * 20
V = 2880π
The answer is therefore the third one down, 2880 π in³