There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

A man who was outside in the rain without an umbrella or hat didn’t get a single hair on his head wet. Why?

One night, a woman receives a call from the police. They tell her that her husband was murdered and that she should come to the crime scene as soon as possible. The woman drops the phone, shocked, and drives 20 minutes to the crime scene. As soon as she reaches the crime scene, the police arrest her and she is convicted of murder. How do the police know she committed the crime?

There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?

Solve the mathematical equation in the picture below.

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

I always drive my customer away.

Who am I?

I am dry when I go inside, but wet when I am pulled outside.
The longer I am inside, the stronger I get
When I am completely out, I am wet and I literally sag
Who am I?