In a contest, four fruits (an apple, a banana, an orange, and a pear) have been placed in four closed boxes (one fruit per box). People may guess which fruit is in which box. 123 people participate in the contest. When the boxes are opened, it turns out that 43 people have guessed none of the fruits correctly, 39 people have guessed one fruit correctly, and 31 people have guessed two fruits correctly.
How many people have guessed three fruits correctly, and how many people have guessed four fruits correctly

A famous swimmer can swim downstream in a lake in exactly 40 minutes with the lake current.
He can swim upstream in that lake in exactly 60 minutes against the lake current.
The length of the lake is 2 km.

How long he can cover the distance of one side at a still lake with no current?

Why is the Hole below a Lock?

There is something which you can be arrested for attempting but not for successfully completing.

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

f you were running a race, and you passed the person in 2nd place, what place would you be in now?

You walk into a room and see a bed. On the bed, there are two dogs, five cats, a giraffe, six cows, and a goose. There are also three doves flying above the bed. How many legs are on the floor?

What has many keys but can’t open a single lock?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

Your mother’s brother’s only brother-in-law is asleep on your couch. Who is asleep on your couch?