You can
put this solution on YOUR website!Hint:
When writing formulas containing duplicate copies of the same letter of the alphabet, such as your formula for the volume,

you must use upper and lower case letters to distinguish between the two variables, otherwise, one cannot make much sense out of the formula. Her's how it should appear:

where: R is the outside radius and r is the inside radius.
a) Rewrite by factoring the right sides.
b) I don't see your graph but if I graph

...the 27 comes from inside radius of r = 3 cm but it's

in the formula:

=
It's a little hard to tell from this graph but when V = 100, then R = 3.7 cm