Can you replace the question mark with the correct number?

What have one eye but still cannot see?

It was a dark stormy night and a couple were in a car driving madly to a city. The car broke down and the husband had to go get help from someone who spoke his language. He was afraid to leave his wife alone in the car so he locked the car before leaving. When he came back, the car was in the same state as he had left it but his wife was dead, there was blood on the floor and there was a stranger in the car. What happened?

Can you name some countries which do not have the alphabet 'A' in them?

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

Four men were in a boat on the lake. The boat turns over, and all four men sink to the bottom of the lake, yet not a single man got wet! Why?

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

There are are five things wrong with this sentence; only geniuses will be able to to spot all of the mitstakes

An equation has been laid down using a few matchsticks. However, as you can see, the equation is not correct. Can you correct the equation if you are allowed to add or remove 5 matchsticks?

There is a place where if I stand up straight, I will still be considered sideways.