If eleven plus two equals one, what does nine plus five equal?

No one wants to have it, but if one got it, he does not want to lose it. What is It?

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

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

You need to complete the maze by entering from the entrance marked below in the figure near the yellow circle, bottom left and leaving from the exit point near the green circle, bottom middle.

Rule of Game: You can move only by exchanging green and yellow circles.

What does this rebus riddle means ?

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

I am a type of room you cannot enter or leave. Raised from the ground below, I could be poisonous or a delicious treat. What am I?

There’s a one-story house in which everything is yellow. Yellow walls, yellow doors, yellow furniture. What colour are the stairs?

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?