What can go up a chimney down, but can’t go down a chimney up?

A mother bought three dress for her triplets daughters(one for each) and put the dresses in the dark. One by one the girls come and pick a dress.
What is the probability that no girl will choose her own dress?

The centre of the third figure is empty. What digit should fit inside?

What four weights can be used to balance from 1 to 30 pounds?

In the Chess Board picture below white army is arranged. You need to add a black army on the board such that no piece is under any threat.
Note: Army comprised of 1 king, 1 queen, 2 rooks, 2 bishops, 2 knights, and 8 pawns.

Can you find out the missing number?

? 4 5 3 5

9 5 7 10 3

what's the probability of getting a king or a queen from a pack of 52 cards?

Can you count the number of triangles in the given figure?

You want to boil a two-minute egg. If you only have a three-minute timer (hourglass), a four-minute timer and a five-minute timer, how can you boil the egg for only two minutes?

You have two buckets of 11 liters and 6 litres.
How can you measure exactly 8 litres?