Henry Ernest Dudeney/Puzzles and Curious Problems/293 - The Twenty Pennies/Solution

Puzzles and Curious Problems by Henry Ernest Dudeney: $293$

The Twenty Pennies

If sixteen pennies are arranged in the form of a square

there will be the same number of pennies in every row, column and each of the long diagonals.

Can you do the same with twenty pennies?

Solution

Start with the square of $16$ pennies in $4$ rows of $4$.

Place:

one penny on the first penny in the first row

one penny on the third penny in the second row

one penny on the fourth penny in the third row

one penny on the second penny in the fourth row.

Sources

• 1932: Henry Ernest Dudeney: Puzzles and Curious Problems ... (previous) ... (next): Solutions: $293$. -- The Twenty Pennies
• 1968: Henry Ernest Dudeney: 536 Puzzles & Curious Problems ... (previous) ... (next): Answers: $436$. The Twenty Pennies