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
We observe that if 288 is multiplied by (2 x 3), then its prime factors will exist in triples.
Thus, the required smallest number by which 288 be multiplied to make it a perfect cube i: (2 x 3), i.e. 6.