Let's say every other person decides to have 8 chocolates instead of 10. They have to give up 2 chocolates each. Now there are some spare chocolates. The last person who only had 2 at first, can now take 6 of these spare chocolates to have a total of 8 also. And it ends that there's 20 left over. So the total number of spare chocolates = 20 + 6 = 26. Since every other person gave 2 up, 26 ÷ 2 = 13. So 13 persons gave up 2 chocolates each. Total number of people sharing = 13 + the 1 last boy = 14