Question

Enter the cube root of 29791, given that it is a perfect cube.

• A. 31

Answer 1

The correct option is A 31
Step 1: Start making groups of 3 digits starting from the unit place.
$\text{i.e.,}\underset{–}{29}\underset{–}{791}$

So, the first group = 791 and the second group = 29

Step 2:
First group i.e., 791 will give us the units digit of the cube root. As 791 ends with 1, the units place of the cube root will be 1.

Step 3:
Now, take second group i.e., 29.
We know that, $3^3<29<4^3$

As the smallest number is 3, it becomes the tens place of the required cube root

$\therefore$$\sqrt[3]{329791}=31$