In one container there are two black beads, in another two white beads, and in a third there are one black and one white bead.
They are labelled appropriately BB, WW, and BW.
Someone moved the labels in such a way that for each container the label doesn't show its contents.
Can you determine the contents of all three containers by withdrawing one bead from one container only?
I guess this is not really humor. It has a logical solution....
Maybe we need a 'Brain Teaser' forum?