I've been very interested in these since an hour ago, and would like to figure out a few I have devised. To solve the problems one estimates how many of a geometrical object will fill a cavity in practice. You might be able to find how many melted jelly beans can fit in a jar, but that's not the same as real ones. The first one I thought of was an oddly shaped jar. It is a truncated ellipsoid, with dimensions 10" high, 7" at widest, and 4.75" thick. Where is it truncated? Part of it was lopped off, leaving a straight edge that goes halfway up to the equator of it, the top and bottom, and left and right sides were lopped off as well. The flat side on the top and bottom, and the flat side on the left and right are the same. The third one is a box, which is 10x10x3 inches. Now, how can we find how many of (the classic) jellybeans can be poured in, making sure to take into account empty space inbetween units? But for an added twist, what about tiny 1x1x1 cm cubes, or Hershey's kisses?