42

How many shades of green? Probably 42, as the number forty-two seems to have been the answer to so many questions in life.

Douglas Adams who wrote The Hitchhikers Guide to the Universe used the number 42 as the answer to the Ultimate Question of Life, the Universe and Everything. The supercomputer took 7 1/2 million years to compute the answer, although the question to which it is the answer remains unknown.

Interestingly, the writer admitted that he simply dreamt up the number as it had to be a number and 42 seemed to be perfect for the job. However, many other things have been named after Adams' 42; Coldplay's track '42', the band Level 42, The Kumars at Number 42 and a Dr Who episode. There is also a radio telescope called 42 which was named by the organisation which searches for little green men (SETI).