1) and 2) were pretty: in 1) there were 3 base triangles in top with 4 lays, plus 2 combinations possible and the entire triangle, those ate 6 combinations, so finally, 6*4 = 24; the question in 2) is ambiguos, "how many balls?", but balls that I can see or should be in there to sustain the structure? Cheap tactic from facebook people, anyway, square numbers addition, 1^2 + 2^2 + 3^2 + 4^2 = 30 sphere should be in there; how many balls I can see, 16 if I remember the pic good.
3) Not native english, not get the "joke" at time. However, no math involved.
4) This one is awful.
5) No math involved neither.
And still no one has resolved my problem.