Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?

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

A family is trapped in a jungle. There is a bridge which can lead them to safety. But at one time, the bridge can only allow two people to pass through. Also, all of them are afraid of the dark and thus, they can't go alone.

Father takes 1 minute to cross, the mother takes 2 minutes, the son takes 4 and the daughter takes 5 minutes. While crossing the time taken will be according to the slower one. How can they all reach the other side in the minimum possible time?

What is the riddle which can be asked all day with a different correct answer each time.

Below rebus represent famous DiCaprio movie. Can you name it?

Prove that the below maths equation is true.

8 + 8 = 91

Do you know of a place where the wind blows south and then suddenly shifts direction towards the north?

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

Why despite killing dozens of people Charley and Wilma were not punished?