At first glance, this might appear to be a simple, playful math problem.
However, there is a subtle point to consider with puzzles like this: there isn't just one single method to obtain that 11-kilogram quantity. It can be achieved in multiple ways, all of which yield the correct solution.
If we haven't yet found a solution to a problem we are working on, it does not mean that no solution exists; it simply means we haven't tried an approach other than the one we are currently using.