Question

By estimation method, $\sqrt[3]{3-13824}=$?

• A. $-24$
• B. $-28$
• C. $-26$
• D. $-34$

Answer 1

The correct option is A $-24$

Given, $-13824$.
The unit's digit of $13824$ is $4,$ so $4$ is the unit's digit of the cube root....[Since, $4^3=64$].
Now, grouping the three digits from the right, the number left is $13.$
We know, $2^3=8<13<27=3^3$.
$\Rightarrow$ $2$ is the ten's digit of the cube root of $13824.$

Then, $24$ is the cube root of $13824.$
$\therefore$ $-24$ is the cube root of $-13824.$

Hence, option $A$ is correct.