If eleven plus two equals one, what does nine plus five equal?

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

Twice ten are six of us,

Six are but three of us,

Nine are but four of us;

What can we possibly be?

Would you know more of us?

Twelve are but six of us,

Five are but four, do you see?

What are we?

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

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.

How many times can you subtract the number 5 from 25?

How can you take 2 from 5 and leave 4?

In four steps you need to move the word 'cold' From 'warm' by replacing one alphabet at a time such that every word formed at each step is acceptable in English Dictionary.

A new Engineering building containing 100 offices had just been completed. John was hired to paint the numbers 1 to 100 on the doors. How many times will John have to paint the number nine (9)?

A person was found dead on a big green land with no trees or buildings around. When the police arrived, they found a piece of rock lying next to him and the man was wearing clothes comprising of red, blue and yellow colours.

Can you tell who the person is and what was the cause of death?