Replace the question mark with the number below given a simple math problem.

A large container is kept in open under the rain. Every passing hour, the water collected inside the container becomes double what it was.

In ten hours, the container is filled completely. Can you calculate how long would it have taken to be filled in half?

How high do you have to count before you use the letter “a” in the English spelling of the whole number?

A train full of passengers goes through a tunnel. When the train comes out from the other end, there is no single person on the train.

How did it happen?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

What you cannot hold but it is yours?

Solve the equation in the image by looking at the pattern closely.

John is 45 years older than his son Jacob. If you find similarities between their ages, both of their ages contain prime numbers as the digits. Also, John's age is the reverse of Jacob's age.

Can you find their ages?

Eight of us go fourth, not back, to protect our king from an attack. What are we?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?