Someone's dog goes around the neighborhood every
night getting into people's garbage pails and
making a mess. Some of the neighborhood kids say
they know what the guilty dog looks like, but
the culprit strikes at night, so it's hard to
see. Each of the four witnesses has one and only
one detail right, and each detail is described
correctly by only one witness.
Dan says the dog is white, fluffy, wears a red
collar, and has a long tail.
Karen says the dog is black, has short hair, wears
a red collar, and has a long tail.
Max says the dog is brown, has long, silky hair,
wears a blue collar, and has a long tail.
Emma says the dog is spotted, fluffy, wears a
red collar, and has a short tail.
Can you correctly describe the guilty pooch?
||The dog is white, has short hair, wears a blue collar,
and has a short tail.
To arrive at the answer, begin by making a chart
like the following:
Next, cross out the details in each column that
are repeated. (only one detail is described correctly
by each witness: the dog can't be fluffy, can't
wear a red collar, and can't have a long tail.)
Now you have all the information you need:
The dog wears a blue collar and has a short tail.
The dog must be white, because Dan is wrong about
the hair, the collar, and the tail, and he has
to be right about one detail.
Max, and Emma are wrong about the dog's color;
therefore the dog must have short hair, because
Emma has to be right about one detail.