Find the missing number in the sequence below:

A man is trapped in a room. The room has only two possible exits doors. Through the first door there is a room constructed from magnifying glass. The blazing hot sun instantly fries anything or anyone that enters. Through the second door there is a fire-breathing dragon. How does the man escape?

What does this Rebus Picture mean?

Which letter of the alphabet has the most water?

There is a shop where written:
Buy 1 for $1
10 for $2
100 for $3
I needed 999 and still only paid $3. How could this be financially viable for the shop-keeper?

A swan sits at the center of a perfectly circular lake. At an edge of the lake stands a ravenous monster waiting to devour the swan. The monster can not enter the water, but it will run around the circumference of the lake to try to catch the swan as soon as it reaches the shore. The monster moves at 4 times the speed of the swan, and it will always move in the direction along the shore that brings it closer to the swan the quickest. Both the swan and the the monster can change directions in an instant.
The swan knows that if it can reach the lake's shore without the monster right on top of it, it can instantly escape into the surrounding forest.

How can the swan successfully escape?

Place the numbers from 1 to 9 in the circles in a manner that each side of the triangle sums up to 17.

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

Why do you find that most of the buildings are deprived of the 13th floor?

I throw two dice simultaneously.

What is the probability of getting a sum as 9 of the two numbers shown?