Question

Find the cube root of $59319$ by estimation method.

• A. $29$
• B. $39$
• C. $49$
• D. $59$

Answer 1

The correct option is B $39$

Step $I$: Form groups of $3$ starting from right most digit of $59319$, i.e. $\overline{59}\overline{319}$.

Then, the two groups are $59$ and $319.$

Here, $59$ has $2$ digit and $319$ has $3$ digit.

Step $II$: Take $319$.

Digit in unit place $=9$.

Therefore, we take one's place of required cube root as $9$ ....[Since, $9^3=729$].

Step $III$: Now, take the other group $59$.

We know, $3^3=27$ and $4^3=64$.

Here, the smallest number among $3$ and $4$ is $3$.

Therefore, we take $3$ as ten's place.

$\therefore \sqrt[3]{359319}=39$.

Hence, option $B$ is correct.