Name a key which is hardest to turn.

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

Using the clues below, what four numbers am I thinking of?

The sum of all the numbers is 31.
One number is odd.
The highest number minus the lowest number is 7.
If you subtract the middle two numbers, it equals two.
There are no duplicate numbers.

You and your two friends are working in a multinational company. How can you three find out the average salary of you all without disclosing your own salary to the other two?

What is the difference between a jeweller and a jailer?

After teaching his class all about Roman numerals (X = 10, IX=9 and so on) the teacher asked his class to draw a single continuous line and turn IX into 6. The teacher's only stipulation was that the pen could not be lifted from the paper until the line was complete.

There is a place where if I stand up straight, I will still be considered sideways.

I am a number I am not an odd number I am higher than 90 I am not higher than 100 If you subtract me from 100, you get nothing. What number am I?

How many points are there on the globe where, by walking one mile south, then one mile east and then one mile north, you would reach the place where you started?

Can you identify the famous TV character from the rebus below?