Question

Find the cube root of 531441.
1. 81
2. 91
3. 71
4. 89
5. None of these.

Answer 1

Correct Answer - Option 1 : 81

Concept used:-

Trick to find cube root of a number.

Method and Calculation:-

 • Find the unit digit of cube root by looking at unit digit of given number.

For cube root of 531441, unit digit must be 1 (1³ is 1)

 • Find other digit(s) by ignoring the last three digits of number and looking at remaining digits.

512 < 531 < 729 (512 and 729 are cubes of 8 and 9, so remaining part of cube root will be 8)

Hence, 81 is our answer.