What is an example of a logic puzzle?
M
ost of us have encountered logic puzzles before, usually on mathematics
tests given in grade and high school. They often contain numbers (the
mathematics connection) and a (often seemingly convoluted) sequence of events
to which the reader has to determine the outcome.For example, the following will jar the memory banks of everyone who has
ever seen such logic puzzles on an exam or elsewhere: One weekend, three peo-
ple check into a bed and breakfast. They pay $30 ($10 each) to the B&B owner
and go to their room. The owner remembers that there is a special deal that
weekend, and the actual room rates come to $25. He gives $5 to his brother
(who works with him) and tells him to return the money to the guests. On the
way to the room, the brother realizes that $5 would be difficult to share between
three people—5/3 1.666 ..., an uneven number—so he pockets $2 and gives
$1 to each person. Therefore, each person paid $10 and got back $1; this means
they paid $9 each, totaling $27. The brother has $2, so the entire total is $29.
Where is the remaining dollar?
The solution? Deduction comes in handy here. It’s the owner who’s impor-
tant to pay attention to, not the brother. Overall, each guest paid $9 (a total of
$27), the owner now has $25, and the brother has $2; thus, the brother’s amount
should be either added to the owner’s money (25 [owner] 2 [brother] 3
[guests] 30), or subtracted from the guests’ amount of $27 (27 [guests] 2
[brother] 5 [refund from owner] 30)—not added to the guests’ amount. This
proves that not only is the owner’s brother a bit dishonest, but also how easy it is
to con some people out of a few dollars if they aren’t used to solving logic puzzles!While on my way to St. Ives,
I met a man with seven wives.
Each wife had seven sacks;
Each sack had seven cats;
Each cat had seven kits.
Kits, cats, sacks, wives;
How many were going to St. Ives?By this time, most people start adding and multiplying, trying to come up with
the answer. But in reality, it’s a trick question: The narrator is on the way to St. Ives;
the group he or she met along the way were leaving, not going to, St. Ives. Therefore,
the number “going to St. Ives” equals (at least) one: the narrator. 427