Which number should replace the question mark?

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

What is the four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?

You need to move three matchsticks to form three squares. Can you do it?

Find the Next Number in the Sequence

2 9 3 1 8 4 3 6 5 7 ?

What is the largest number you can write with just 3 digits?

A farmer and his neighbour once went to Emperor Akbar"s court with a complaint. "Your Majesty, I bought a well from him," said the farmer pointing to his neighbour, "and now he wants me to pay for the water."
"That"s right, your Majesty," said the neighbour. "I sold him the well but not the water!"?
The Emperor asked Birbal to settle the dispute. How did Birbal solve the dispute?

You are stuck on an island where you have nothing. You find four pieces of paper somewhere on the island. What will be your strategy to escape from the island safely?

PS: No other resource is available to you on the island, neither can you build anything.

Can you find a five letter word that is left with only two letters if one is removed?

This is a classy optical illusion puzzle. What more you can find except bricks in the image below?