
Place ten pennies on a large sheet of paper or
cardboard, as shown in the diagram, five on each edge.
Now remove four
of the coins, without disturbing the others, and replace them on the
paper so that the ten shall form five straight lines with four coins in
every line.
Try to
discover in how many different ways the puzzle may be solved, assuming
that in every case the two rows at starting are exactly the same.
See answer
