-=Dark_Angel=-, P.I.3 Mar 2006

100 reversible black/white counters are in a darkened room. Call a counter White if its white side is facing up. Call it Black if its black side is facing up. You know that 90 of the 100 counters are Black and 10 are White. Arrange the counters into two distinct piles, each with the same number of Whites. (Obviously you cannot see the counters, merely fondle them. And flip them if you want.) [10 marks]