The BrainBashers mechanical computer is a very sensitive device, in consists of four sequential cog wheels which are in constant mesh.

The largest cog has 63 teeth and the others have 42, 35 and 27 respectively.

By accident, Daniel started to rotate the largest cog.

How many revolutions must he rotate the largest cog make before the computer is back in its starting position with all of the cogs where they started?

By changing the second letter of each word below, you can make another valid word.

Can you change each word such that the second letters will reveal an eleven letter word when read downwards.

Therefore, what now reads AWPYRNUCEPA will be a real word.

BAKE
SWAP
OPAL
DYED
ARKS
SNOW
LUMP
ACES
MELT
SPUN
RANT

Below you will find 15 well-known six letter words, with only their endings remaining. Can you determine the words?

...cil
...hid
...nze
...ese
...lug
...som
...uxe
...uum
...arm
...amo
...rby
...dst
...sai
...too
...fen

Are there more millimetres in a mile or sixteenths of inch in 2 kilometres?