Quicken Your Mind

The book Problems for Quickening a Young Mind is believed to have been
written c. 800 A.D. by Alcuin of York, Abbot of St. Martin of Tours.
Many of the puzzles in it, however, apparently come from older Arabic
sources.  Here are some examples:

"A dog and a hare are 150 feet apart.  The dogs follows when the hare
runs.  The dog leaps 9 feet at a time, while the hare travels 7 feet.
How many feet will be travelled by the pursuing dog, and the fleeing
hare, before it is seized?"

"A certain gentleman ordered that ninety measures of grain were to be
moved from one of his houses to another, thirty half-leagues away.  One
camel was to transport the grain in three journeys, carrying thirty
measures on each journey.  A camel eats one measure each half-league.
How many measures will be left, when all has been transported?"

"Three men, each with a sister, needed to cross a river.  Each one of
them coveted the sister of another.  At the river, they found only a
small boat, in which only two of them could cross at a time.  How did
they cross the river, without any of the women being defiled by the
men?"

These problems and many others are in Dominic Olivastro's Ancient
Puzzles, ISBN 0-553-37297-1, Bantam 1993.  Enjoy!

Joshua ibn-Eleazar ha-Shalib

from the May 1997 Seahorse