Answer :
The secret of the bun puzzle lies in the fact
that, with the relative dimensions of the circles as given, the three
diameters will form a rightangled triangle, as shown by A, B, C.
It
follows that the two smaller buns are exactly equal to the large bun.
Therefore, if we give David and Edgar the two halves marked D and E,
they will have their fair shares—one quarter of the
confectionery each.
Then if we place the small bun, H, on the top of
the remaining one and trace its circumference in the manner shown,
Fred's piece, F, will exactly equal Harry's small bun, H, with the
addition of the piece marked G—half the rim of the other.
Thus each boy gets an exactly equal share, and there are only five
pieces necessary.
