What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

People are waiting in line to board a 100-seat aeroplane. Steve is the first person in the line. He gets on the plane but suddenly can't remember what his seat number is, so he picks a seat at random. After that, each person who gets on the plane sits in their assigned seat if it's available, otherwise, they will choose an open seat at random to sit in. The flight is full and you are last in line. What is the probability that you get to sit in your assigned seat?

O_er_t_o_

Complete the missing letters of the given word.

When you stop to look, you can always see me. But if you try to touch me, you can never feel me. Although you walk towards me, I remain the same distance from you. What am I?

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

Which letter of the alphabet has the most water?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

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