The answer is 67.50 because you multiply 90$ by .25 than you got 22.50 subtract 22.50 by 90
First of all, you surely do have a lot of incorrect grammar in your statement. I can't understand a word that you are asking.
Start with the parentheses
Assuming you're just computing the volume, i.e.

we should convert to cylindrical coordinates first, setting

so that the volume is given by

which has a value of

.