What is wrong in the below Picture?

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

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

By moving exactly three matchsticks can you make the below equation true.It can be solved by 3 ways.

You need to climb ten stairs. At every stair, you can either take one step up or you can jump two steps up.

In how many different ways you can climb 10 stairs?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

John killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

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

See the given image carefully. What you have to do is move the blue checkers in the position of the black checkers and vice versa. You are only allowed to move the checker to an adjacent empty space. Do it in the least possible moves.

You’ll find me on Mercury, Earth, Mars, Jupiter, Saturn, and Uranus. But never Neptune, or Venus. What am I?