232.--CATCHING THE MICE.

[Illustration]

"Play fair!" said the mice. "You know the rules of the game."

"Yes, I know the rules," said the cat. "I've got to go round and round

the circle, in the direction that you are looking, and eat every

thirteenth mouse, but I must keep the white mouse for a tit-bit at the

finish. Thirteen is an unlucky number, but I will do my best to oblige

you."

"Hurry up, then!" shouted the mice.

"Give a fellow time to think," said the cat. "I don't know which of you

to start at. I must figure it out."

While the cat was working out the puzzle he fell asleep, and, the spell

being thus broken, the mice returned home in safety. At which mouse

should the cat have started the count in order that the white mouse

should be the last eaten?

When the reader has solved that little puzzle, here is a second one for

him. What is the smallest number that the cat can count round and round

the circle, if he must start at the white mouse (calling that "one" in

the count) and still eat the white mouse last of all?

And as a third puzzle try to discover what is the smallest number that

the cat can count round and round if she must start at the white mouse

(calling that "one") and make the white mouse the third eaten.

Amusements in Mathematics · 第 264 / 970 题