Find the value of "?" in the ball picture Riddle below:

You stand in front of two doors. A guard stands next to each door. You know the following things: one path leads to paradise, the other leads to death. You cannot distinguish between the two doors. You also know that one of the two guards always tells the truth and the other always lies. You have permission to ask one guard one question to discover which door leads to paradise. What one question would you ask to guarantee you enter the door to paradise?

If a zookeeper had 100 pairs of animals in her zoo, and two pairs of babies are born for each one of the original animals, then (sadly) 23 animals don’t survive, how many animals do you have left in total?

A man says, "Brothers and sisters, have I none, but that man's father is my father's son." Who is that man?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

How many words can a pen with half refill write?

Here is a mathematical expression that also secretly tells a movie name. What movie is that?

There was an aeroplane crash, every single person died, but two people survived. How is this possible?

In which direction should the missing arrow point?

2, 3, 5, 9, 17, _ What is the next number in the sequence?