Find the Next Number in the Sequence

2 9 3 1 8 4 3 6 5 7 ?

If it took eight men ten hours to build a wall, how long would it take four men to build it?

Find the number of squares in the below-given picture.

How many people must be gathered together in a room, before you can be certain that there is a greater than 50/50 chance that at least two of them have the same birthday?

Which English verb becomes past tense just by rearranging the letters?

A man walked into a pub and went straight towards the Barman. He asked for a dirty martini from the Barman. The Barman thought something and then pulled out a pistol from his drawer and aimed it directly at the man. Why did he do that?

You can hear me, but you can't touch or see me.

What am I?

Using mathematical symbols like +, -, and x in order to make the equations correct. Replace # with the above-given symbols.

9 # 8 # 7 # 6 # 5 # 4 = 91

One night, a man runs away from home. He turns left and keeps running. After some time he turns left again and keeps running. Later, he turns left one more time and runs back home—but when he gets home, he finds a man in a mask. Who was the man in the mask?

I am an odd number. Take away a letter and I become even. What number am I?