The formula gives the volume v of a right cylinder with radius r and height h.

v=πr²h solve for r.

explain your answer. should either answer be discarded? why or why not?

see explanation

Step-by-step explanation:

Isolate r² by dividing both sides by πh

r² =

Take the square root of both sides

r = ±

The negative part can be  discarded as r > 0, hence

r =

(n^3 - n)

= n(n-1)(n+1)

since it is divisible by 3 and 2 ,because it is a multiple 3 consecutive number

if, n-1 is odd then n+1 is also odd, then it is a multiple of 9

but if, n-1 is even then n+1 is also even, then it is a multiple of 4

so, largest multiple = max(9*2, 4*3) = max(18, 12) = 18

its the fourth option