Out of four images which one is the odd one out?

What is the coolest letter in the alphabet?

What word begins and ends with an E, but has only one letter?

A man is found dead in his bathroom naked with blood scattered all around him. The bathroom was locked from the inside and there is no trace of any struggle. There is nothing in the bathroom except his pant with the belt still around and his shirt. Also, the medic team can't find any incision in his body that may have been the reason behind so much blood loss.

The Police department is clueless regarding this murder mystery.
Can you?

When is the top of a mountain similar to a savings account?

A woman lives in a skyscraper thirty-six floors high and is served by several elevators which stop at each floor going up and down. Each morning she leaves her apartment and goes to one of the elevators. Whichever one she takes is three times more likely to be going up than down. Why?

The husband and wife were jogging in the morning. To match every two steps of the husband, the wife required three steps. If Both of them start with the here right foot. After how many steps do their left foot be together?

What happened when the wheel was invented?

What number do you get when you multiply all of the numbers on a telephone's number pad?

Complete the series by replacing "?" with the correct number.

ST ND RD TH '?'