What is always in front of you but can’t be seen?

Can you find out the smallest number that can be conveyed as the sum of three squares in three unique ways?

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

What can run but never walk, have a mouth that never speaks, have a head that never weeps, and have a bed but never sleeps?

Fate has decided that you will only be pleased to meet me when you need me

Maybe that is why, when I am working, I start working

However annoying I may be to the regulars, the little ones are always inspired

I will always be waiting if you try to reach me

How many of you can guess my name, let me see

What numbers should go on the bottom line?
3 6 9 15
8 2 10 12
11 8 19 27
19 10 29 39
? ? ? ?

When Jack was six years old he hammered a nail into his favourite tree to mark his height. Ten years later at age sixteen, Jack returned to see how much higher the nail was. If the tree grew by five centimetres each year, how much higher would the nail be?

Which is the correct shadow of the bird?

Can you name some countries which do not have the alphabet 'A' in them?

Can you find the least possible number such that

If the number is divided by 3, it gives the remainder of 1;
If the number is divided by 4, it gives the remainder of 2;
If the number is divided by 5, it gives the remainder of 3;
If the number is divided by 6, it gives the remainder of 4.