Henry Ernest Dudeney/Puzzles and Curious Problems/247 - The Counter Cross/Solution

by : $247$

 * The Counter Cross

Solution
There are $21$ squares:


 * Dudeney-Puzzles-and-Curious-Problems-247-solution.png


 * $9$ of them will be of the size indicated by the four instances of $\text a$
 * $4$ of them will be of the size indicated by the four instances of $\text b$
 * $4$ of them will be of the size indicated by the four instances of $\text c$
 * $2$ of them will be of the size indicated by the four instances of $\text d$
 * $2$ of them will be of the size indicated by the four instances of $\text f$.

These are indicated by the blue dotted squares in the above diagram.

If you now remove all counters marked $\text e$, no squares can be formed from the remaining counters.