More Free Puzzles
Here are some more free riddles and puzzles. There is no subscription
fee, and never any pop-ups either (I hate those things). These
are some of the puzzles that have appeared in the Brainpower
Newsletter (you can click on that link for more information
about the newsletter). The solutions are at the bottom of the
page. Good luck!
1. While walking, you come to a fork in the road. You don't
know which way to go to reach your destination, but there are
two computers there - one programmed to always tell the truth
while the other always tells a lie. The problem is that you don't
know which is which, and you get to ask only one question of
either computer to find the right way. Which computer do you
ask, and what is the question?
2. Three very intelligent monkeys came to a river that was
wide and deep. Unfortunately, they didn't know how to swim, and
there were no materials nearby to make a bridge. However, they
were across in just a few minutes. How did they cross the river?
3. A woman is driving off-road in the middle of the desert
and she gets a flat tire. She takes the spare tire out of the
trunk, and then removes the flat one. She accidentally drops
all four lug nuts (the nuts that hold the tire on) down a hole
that is ten feet deep and only a few inches wide. She'll die
of thirst if she can't find a way to put that spare tire on securely
enough to drive out of the desert. Just using what is normally
available in any car, can you come up with at least two ways
to solve this problem?
(This is really a lateral thinking puzzle, and there are undoubtedly
many creative solutions. Two possibilities are given below.)
Solutions to the Puzzles
1. Just ask either computer: "If I asked the other computer
if I should go left, would he say yes?" If the road to the
left is the correct direction, the honest computer will say "no"
because the other would lie. The dishonest one would also say
"no" because it has to lie about what the other would
say. So if either answers "no" you should take the
road to the left. Conversely, a "yes" answer means
the road to the right is the correct one to take.
2. They crossed it in winter, when they could simply walk
across on the ice.
3. Two of the many possibilities:
-1: Break loose a speaker and remove the magnet. Then pull
ten feet of wire loose in the trunk or other part of the car
(where they aren't necessary for the car to run). Knot several
pieces together if necessary, tie the magnet to the end and lower
it down the hole. The magnet should pick up the lug nuts easily.
-2: Remove one lug nut from each of the other three tires
and use these three to put on the spare. This should be sufficiently
secure until a town can be reached.