Question #ef673

1 Answer
Sep 27, 2017

The answer is C). 18.

Explanation:

If x and y are two perfect cube numbers, they can be written as
#x#=#m^3# and #y#=#n^3# for some integer (#m,n#).

This means #xy#=#m^3n^3#=#(mn)^3# is also a perfect cube number. So #a#,#b#,#c# and #a+b+c# must be a multiple of 3.