Q.2 Find the smallest number by which each of the following numbers must be multiplied to obtain a perfect cube.
(i) 243
(ii) 256
(iii) 72
(iv) 675
(v) 100
This can be found by knowing about the prime factors of the number.
(i) 243 : .
So it must be multiplied by 3.
(ii) 256 :
So the given number must be multiplied by 2 to make it a perfect cube.
(iii) 72 :
So 72 must be multiplied by 3 to make it a perfect cube.
(iv) 675 :
So it should be multiplied by 5.
(v) 100 :
So it should be multiplied by 10.