Can you find the key in the picture below?

A girl has as many brothers as sisters, but each brother has only half as many brothers as sisters. How many brothers and sisters are there in the family?

What is both possible and impossible at the same time?

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

A detective visits his friend John just to discover that John's neighbour Dr Jacob was murdered. Dr Jacob, who is a mathematician wrote the murderer's name in a code word "Hcqtfz". There were five suspects
1. Ajit
2. Pankaj
3. Ganpat
4. Deenu
5. Hariya

The Detective was instantly able to find the murderer.
Can you?

Can you replace the question mark with the correct number?

A man who was outside in the rain without an umbrella or hat didn’t get a single hair on his head wet. Why?

81 x 9 = 801. What must you do to make the this equation true?

John was working on a Chemical Mixture whose weight comprise 90% liquid and 10% solid. The total weight of the mixture is 20 pounds. After a while, John noticed that some of the liquid evaporated and now the liquid comprises just 50% of the weight.

What is the weight of the chemical mixture now?