Logic riddles

Geese

Two geese before a goose, And two geese behind a goose And one goose in the middle. How many geese in all?

Three, one behind the other in а row.

Sugar

Can you place ten pieces of sugar in three cups so that every cup contains an odd number of pieces?

This puzzle is sometimes asked as an interview question. It also makes for a fun problem at parties and pubs. One way of solving this is to place 3 pieces in one cup and 7 in another; then place the second cup in the third cup.  Instead of pieces of sugar this problem is also known as 10 coins in 3 cups. As you can see in the photo below, one way of solving this is to put 3 coins in first cup, 3 into the second, and 4 into the third cup, and then place the third cup into the second cup. Read more about this problem HERE

Two people

Two persons are standing near one another. One is looking southward, the other northward. How can they see each other without turning their heads and without using looking-glasses?

They are facing each other.

MORE RIDDLES

hawk & doves

A hawk saw a flock of doves and said, “Hello, my hundred doves!” They answered, “We are not a hundred doves. To be so many would take us, and as many as us, and half as many as us, and a quarter as many as us, and you, Mr Hawk!” How many doves did the hawk see? 

Thirty-six doves.

Family

I have an equal number of sisters and brothers; but my sister has twice as few sisters as brothers.

How many are we?

4 brothers and 3 sisters. Each brother has 3 brothers and 3 sisters, and each sister has 4 brothers and two sisters.

Nine

How many 9’s between 1 and 100?

20

MORE PUZZLES

Salesman

John Smith bought a used car for $600 and sold it to Mary Baker for $800. He later bought it back for $1000 and resold it for $1200. How much profit did John make?

$400

The drive

A taxi driver was called to take a group of passengers to the train station. The station is normally an hour away, but with traffic being extra heavy, it took a full hour and a half. On the return trip the traffic was still as heavy but it took only 90 minutes. Why?

1 hours is the same as 90 minutes. Times it’s unchanging

More Riddles

There is a frog stuck in a 60 foot well. How many days will it take the frog to get out if for every day he jumps five feet up, but then falls back three feet?

29 days. The last jump he was out of the well so he did not fall three feet back.



A boy and a doctor were fishing. The boy was the doctor's son but doctor was not the boy's father. Who is the doctor?

His mother



Some octopuses, some fish and a few mermaids were happily frolicking in a rock pool. Altogether there were 38 arms, 24 eyes and 8 tails all swimming in the pool. How many mermaids were there?

There must be 3 mermaids.

This is helpful information that can be deduced: Fish don’t have arms so the arms come from the octopuses and the mermaids. All of the creatures have two eyes and since there are 24 eyes there must be 12 creatures. Octopuses don’t have tails so there are 8 fish and mermaids.

Therefore, there are 12 creatures, 8 of which are fish and mermaids, and 12 – 8 = 4 octopuses.

4 octopuses contribute 4 x 8 = 32 arms. That leaves 38 – 32 = 6 arms for the mermaids. There must be 3 mermaids.

Lions

How many lions can enter an empty cage?

Only one. After that the cage is not empty.

Sand

How much sand is there in a hole, dug in the ground, one metre in diameter and one metre in depth?

None

cats

There are four corners in the room. There is one cat in each corner. There are three cats in front of each cat. 

How many cats are there in the room?

Four cats