Question

A. 65 cm^3
B. 78 cm^3
C. 81 cm^3
D. 93 cm^3

Answer 1

Lets get this :)

Volume(big cylinder) =
`\pi r^2h`
2187 =
`\pi r^2(3)`

`(2187)/(3) = \pi r^2`
729 =
`\pi r^2`

`(729)/( \pi ) = r^2`
r =
`\sqrt{ (729)/( \pi ) }`
r ≈ 15.2 cm (radius of big cylinder)

The ratio of big cylinder to small one is:
3 : 1

Therefore, the big cylinder is 3 times bigger than the small cylinder


`(15.2)/(3)` = r
r = 5.1 cm (radius of small cylinder)

V(small cylinder) =
`\pi (5.1)^2(1)`
= 81 cm³

Your answer is C. 81 cm³