Suppose that once a week, ten men go out for beer and the bill for all ten comes to £100. If they paid their bill the way we pay our taxes, it would go something like this.

The first four men (the poorest) would pay nothing.
 The fifth would pay £1. The sixth would pay £3. The seventh would pay £7. The eighth would pay £12. The ninth would pay £18. 
And the tenth man (the richest) would pay £59. Read More