Henry Ernest Dudeney/Puzzles and Curious Problems/26 - Cross and Coins

Puzzles and Curious Problems by Henry Ernest Dudeney: $26$

Cross and Coins

Here is an interesting little puzzle that will probably keep the reader amused for some moments.

Take any $11$ of the $12$ current coins of the realm,

and using one duplicate coin, can you place the $12$ coins, one in each division of the cross,

so that they add up to the same value in the upright and in the horizontal?

To prevent any possible misunderstanding, the $12$ current coins are of the value of $\pounds 1$, $10 \shillings$, $5 \shillings$, $4 \shillings$, $2 \shillings 6 \oldpence$, $2 \shillings$, $1 \shillings$, $6 \oldpence$, $3 \oldpence$, $1 \oldpence$, $\tfrac 1 2 \oldpence$, $\tfrac 1 4 \oldpence$.

Now remember, there must be $11$ coins all of different value and only one duplicate.

You see, the puzzle is to determine which coin we shall duplicate,

and then so to arrange them that both rows shall add up alike when the question arises which coin shall be placed at the crossing to be twice added?

Sources

• 1932: Henry Ernest Dudeney: Puzzles and Curious Problems ... (previous) ... (next): Arithmetical and Algebraical Problems: Money Puzzles: $26$. -- Cross and Coins