Question

Find the cube root of: $-216$.

• A. $36$
• B. $-36$
• C. $6$
• D. $-6$

Answer 1

The correct option is D $-6$

On prime factorising, we get,

$216=\underset{–}{3\times 3\times 3}\times \underset{–}{2\times 2\times 2}$

$=3^3\times 2^3=6^3$.

Then, $-216$ $=(-6{)}^3$.

Therefore, cube root of $-216$ is:

$\sqrt[3]{3-216}=\sqrt[3]{3(-6{)}^3}=-6$.

Therefore, option $D$ is correct.