Question

Find the cube root of 29791 by estimation method.

• A. 31
• B. 21
• C. 51
• D. 45

Answer 1

The correct option is A 31

Step 1: Start making groups of 3 digits starting from the unit place.
i.e. 29 791
Second group First group

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