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

What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

100 prisoners are stuck in the prison in solitary cells. The warden of the prison got bored one day and offered them a challenge. He will put one prisoner per day, selected at random (a prisoner can be selected more than once), into a special room with a light bulb and a switch which controls the bulb. No other prisoners can see or control the light bulb. The prisoner in the special room can either turn on the bulb, turn off the bulb or do nothing. On any day, the prisoners can stop this process and say "Every prisoner has been in the special room at least once". If that happens to be true, all the prisoners will be set free. If it is false, then all the prisoners will be executed. The prisoners are given some time to discuss and figure out a solution. How do they ensure they all go free?

What month of the year has 28 days?

What has 88 keys?

There's one "sport" in which neither the spectators nor the participants know the score or the leader until the contest ends.

What is it?

The Federal bank of London is abducted by the robbers. The head of the robbers asked the cashier to empty their money vault to them and when suddenly cashier got a call from her father. To avoid any suspicion, the robber asked the cashier to pick the call and reply her father in the shortest manner possible.

The cashier told her father "Is there an emergency father, Call me when you are free and I will help you in your furnishing" and then the cashier hung up the phone.

After 10 minutes, police arrived at the crime scene.

How did the police know about the robbery?

Find the next number in the sequence

5 12 24 36 ?

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?

The answer I give is yes, but what I mean is no. What was the question?