& Alper Ariburnu (Age 8, Private IRMAK Primary and Secondary School Maths Club, Istanbul, Turkey)

"We discussed your Mixed-up Socks question in our Math club hour and we found the answer using coloured pens. We made a combination using three socks. When we made pairs with red and blue socks, the other green and red socks, third pair must be green and blue. We found only one way.

But for four pairs of socks we found 3 ways. (For example if the 4th pair is purple)

1. Green-Blue ,Green-Purple ,Red-Purple, Red-Blue
   
2. Red-green, Green-Purple, Purple-Blue, Red-Blue
   
3. Green-Blue, Red-Purple, Purple-Blue, Red-Green "