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?

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?

I am lying and I always lie. Tell me whether I am lying or telling the truth.

You want to boil a two-minute egg. If you only have a three-minute timer (hourglass), a four-minute timer and a five-minute timer, how can you boil the egg for only two minutes?

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day

There is something which you can be arrested for attempting but not for successfully completing.

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

It spends most of its day eating white, but when it’s quick enough, it gets to eat fruit and sometimes some blue things. It’s in a dark room, where the walls are blue, it runs from a ghost that roams the halls and haunts it all the time. What is it?

I am a word that begins with the letter “i.” If you add the letter “a” to me, I become a new word with a different meaning, but that sounds exactly the same. What word am I?

Keyboard words are not in alphabetical order, Why?