The first of these puzzles is based on a similar principle, though it is really much easier, because the condition that nine of the stamps must be of different values makes their selection a simple matter, though how they are to be placed requires a little thought or trial until one knows the rule respecting putting the fractions in the corners. I give the solution.
I also show the solution to the second stamp puzzle. All the columns, rows, and diagonals add up 1 s. 6 d. There is no stamp on one square, and the conditions did not forbid this omission. The stamps at present in