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!

Why is the Hole below a Lock?

You have two strings whose only known property is that when you light one end of either string it takes exactly one hour to burn. The rate at which the strings will burn is completely random and each string is different.

How do you measure 45 minutes?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

I am not a bull but I have horns.
I am not an ass but I have a pack saddle.
Wherever I go, I leave silver behind me.

Who am I?

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

A man who was outside in the rain without an umbrella or hat didn’t get a single hair on his head wet. Why?

A man hijacks an aeroplane transporting both passengers(8 of them) and valuable cargo. After taking the cargo, the man demands nine parachutes, puts one of them on, and jumps, leaving the other eight behind. Why did he want eight?