64
Though I myself shut up may be,
My work is to set prisoners free.
No slave his lord’s commands obeys
With more insinuating ways.
All find me handy, sharp, and bright,
Where men in wit and wine delight;
While many keep me for their ease,
And turn and twist me as they please.
No. LXVI.—COIN COUNTING
Place ten coins in a circle, as is shown in this diagram, so that on all of them the king’s head is uppermost.
Now start from any coin you choose, calling it 1, the next 2, and so on, and turn the fourth, so that the tail is uppermost. Start again on any king’s head, and again turn the fourth, and continue to do this until all but one are turned.
Coins already turned are reckoned in the counting, but the count of “four” must fall on an unturned coin.
Can you find a plan for turning all the coins but one in this way without ever failing to count four upon a fresh spot, and to start on an unturned coin?