Can you circle exactly four of these numbers such that the total is twelve?

1 6 1
6 1 6
1 6 1
6 1 6

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?

There was an aeroplane crash, every single person died, but two people survived. How is this possible?

While house hunting in London, I came across a very good leasehold property Discussing the lease the landlady told me:

'The property was originally on a 99 years lease and two-thirds of the time passed is equal to four-fifths of the time to come. Now work it out for yourself and see how many years are to go!

How many letters are in the alphabet?

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

A man and a dog were going down the street. The man rode, yet walked. What was the dog’s name?

Which digit occurred maximum times between the number 1 and 1000?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

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