WHAT ARE MATCHES MADE OF?
Arrange fourteen matches as in [Fig. 22], and tell your friends to take away any three matches they may select without disturbing the others, and replace one in any position they may choose in such a way as to show what matches are made of. They will endeavour to form the word “wood”; but [Fig. 23] gives the correct solution.
Fig. 22.
Fig. 23.
A SHEEP PEN
Arrange eight matches as shown in [Fig. 24], and state that this enclosure, formed by eight hurdles, is supposed to hold one hundred sheep. Ask your friends how many 67 more hurdles would be required to enable the enclosure to contain two hundred sheep? The reply is generally eight more, and your friends will be surprised to learn that only two more hurdles are required—one at each end across the enclosure. Three hurdles being moved to admit of the introduction of the additional two, the pen will, of course, be doubled in size.
Fig. 24.