
Pretend that the above is drawn on a piece of paper, draw 4 lines with an imaginary pen w/o lifting the pen so that the lines go through all the dots using only 4 lines.

Pretend that the above is drawn on a piece of paper, draw 4 lines with an imaginary pen w/o lifting the pen so that the lines go through all the dots using only 4 lines.

Move six matches in such a way that you get a house instead of these wine glasses.

An airplane flying at several thousand feet casts a shadow on the ground. Will the shadow be larger, smaller or the same size as the airplane? Why?

Each of the five interlocking gears possess letters at its contact point. (The numbers next to the gear specifies how many teeth the gear has.) After a certain number of revolutions, the letters at the four contact points will spell out an eight-letter word, read from left to right.
Can you make out how many revolutions it will take and what the secret word is?

In this figure, which area is larger, Area 1 or Area 5? How much is the difference?

What goes around the world but stays in a corner?
A Hamiltonian Circuit is a continuous path that passes once through each point of a graph. Can you find the Hamiltonian Circuit for the 11-point graph illustrated here?


Slice the picture into 2 sections from which you could make an 8×8 square.

This picture shows two large triangles, each made up of a number of pieces, each a rearrangement of the other. But one has a square missing. How can this be?