What's the only room from which no one can enter or leave

How many triangles are there on the puzzle below?

Outside a massage parlour, there is a board that reads
"I only massage those who do not massage themselves."

Reading the above statement, does the masseur massage himself?

What does a man do only once in his lifetime, but women do once a year after they are 29?

I have two coins.
* One of the coins is a faulty coin having a tail on both sides of it.
* The other coin is a perfect coin (heads on side and tail on other).

I blindfold myself and pick a coin and put the coin on the table. The face of the coin towards the sky is the tail.

What is the probability that another side is also tail?

Find out which of the given views in the picture is accurately the top view of the given pyramid.

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

The first box has two white balls. The second box has two black balls. The third box has a white and a black ball.

Boxes are labeled but all labels are wrong!

You are allowed to open one box, pick one ball at random, see its colour and put it back into the box, without seeing the colour of the other ball.

How many such operations are necessary to correctly label the boxes?

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

John has played 50 ODI's and his average is 50. How many runs should he score in his 51st ODI, so that his average score jumps to 51?