Question

What is the value of cube root of $4913$ ?

Use estimation method to find the cube root.

• A. $18$
• B. $15$
• C. $16$
• D. $17$

Answer 1

Answer: (D)

$17$

Step $I$ : Form groups of $3$ starting from right most digit of $4913$, i.e. $\overline{4}\overline{913}$

Then, the two groups are $4$ and $913.$

Here, $4$ has only $1$ digit and $913$ has $3$ digits.

Step $II$ : Take $913$

Digit in unit place $=3$

Therefore, we take one's place of required cube root as $7$ .... [Since, $7^3=343$]

Step $III$ : Now, take the other group $4$

We search for the largest cube number which is less than the number in the second group.

Number in the second group is $4$

And also, we know, $1\le 4<8$

$\Rightarrow 1^3\le 4<2^3$

Here, the smallest number among $1$ and $2$ is $1$

Therefore, we take $1$ as ten's place.

$\therefore \sqrt[3]{34913}=17$

Hence, option $D$ is correct.