Is 216 a perfect cube? What is the number whose cube is 216?
We have 216
i.e. Resolving 216 into prime factors we have: 216 = 2 x 2 x 2 x 3x 3 x 3
i.e. 216 can be resolved in to such prime factor which can be grouped into triple of equal of factor and no factor is left over.
∴ 216 is a perfect cube
Thus, the required number is 6, whose cube is 216.
Find the smallest number by which each of the following numbers must be divided to obtain a perfect cube. (i) 81 (ii) 128 (iii) 135 (iv) 192 (v) 704