It is an assignment problem for 11-years-old kids.
There is a water cubic container of length 10cm. The depth of water in the container is 4 cm. Three identical right circular cones are put into the container and the water level rises by 6 cm. No water flows out of the container. Find the volume of a cylinder.
Of course, this is an easy one. But I wonder whether it is possible to put three identical circular cones, each of volume $200\,\textrm{cm}^3$, into the tank so that the water does not flow out. My problem is
Given the dimensions of a rectangular container, what is the maximum total volume of $n$ identical right circular cones can be put completely inside the container?
I have no idea for the cases of $n\ge2$.