John is asked to stand behind Jacob and Jacob is asked to stand behind John. Both of them feel confused about it and don't know what to do?

But it is quite possible, do you know how?

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

Which statement is true out of the following?
One statement here is false.
Two statements here are false.
Three statements here are false.

Can you place six X (crosses) in below board without making three in a row in any way ?

Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?

Which Number is the odd one out?

A) 7145
B) 2716
C) 5321
D) 4135

Replace The Question Mark Below With the Correct Number.

2 {38} 3
4 {1524} 5
6 {3548} 7
8 {????} 9

What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

If I put in one bird per cage, I have one bird too many. If I put in two bird per cage, I have one cage too many. How many cages and birds do I have?