Question

Find the smallest number by which $128$ must be divided so that the result is a perfect cube.

Answer 1

$128=\underset{–}{2\times 2\times 2}\times \underset{–}{2\times 2\times 2}\times 2$
Now, if we try to group together triples of equal factors, we are left with a single factor, $2$.
Hence, to make $128$ a perfect cube, it must be divided by $2$.