There is a box in which distinct numbered balls have been kept. You have to pick two balls randomly from the lot.

If someone is offering you a 2 to 1 odds that the numbers will be relatively prime, for example
If the balls you picked had the numbers 6 and 13, you lose $1.
If the balls you picked had the numbers 5 and 25, you win $2.

Will you accept that bet?

Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?

My cousin lives in one story house in Antarctica. His house is made the of-of sandstone. what is the color of stairs?

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

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

Can you find the six hidden animals in the picture below?

In the picture, you can see a chess board. On the top left position, the K marks a knight. Now, can you move the knight in a manner that after 63 moves, the knight has been placed at all the squares exactly once excluding the starting square?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

A thief enters a store and threatens the clerk, forcing her to open the safe. The clerk says, “The code for the safe is different every day, and if you hurt me you’ll never get the code.” But the thief manages to guess the code on his own. How did he do it?