# The volumes of two spheres are #729# #i n^3# and #27# #i n^3#. What is the ratio of their radii, rounded to the nearest whole number?

##### 3 Answers

**The ratio of their radii is**

#### Explanation:

Volume of bigger sphere is

Volume of smaller sphere is

The ratio of their radii is

The ratio of their radii=

#### Explanation:

Vol. of a sphere=

multiply both sides by

multiply both sides by

Ratios are always in simplest form, so

However we are given the ratios as

Big sphere : small sphere, so the ratio is

#### Explanation:

All spheres are similar figures.

Their volumes are in the same ratio as the cubes of their radii.

Note that we are not asked to find the actual lengths of their radii, only the ratio.

Find the cube root of both sides.

The ratio

Ratios are always given in the simplest form.