why number 8549176320 is one of a kind?

Find The Missing Number In the Sequence.
6 25 64 ? 32 1

Why is the Hole below a Lock?

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?

There was a man he lives in a hotel each morning he presses the first floor button each evening if there is a person in the elevator he asks him to press the 10 floor button if there is no one in the elevator he takes the stairs why.

Which alphabet letter is a question?

The centre of the third figure is empty. What digit should fit inside?

On a bright sunny day, two fathers took their son fishing in the lake. Each man and son were able to catch one fish. When they returned to their camp, there were only three fishes in the basket. What happened?

PS: None of the fish were eaten, lost, or thrown back.

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

What time is it when an elephant sits on a fence?