Thursday, 6 January 2011


Dear friends,
Romania team wishes you a full year as the accomplishments both professionally and on the family.
We start the year with a problem that we propose: Crayons
All the best
Marcu Eugenia


In a box 8 crayons are red and 6 green. How many times you have to extract, without looking inside the box, but certainly extract 2 green?

1 comment:

  1. It's very funny that you've posted this problem this week, because we (Monte Flor's team - Portugal)have been solving some problems of this kind, durind the past days. So, on Friday we also tried to solve your's. Some students reach quickly the solution and others not so well, because they always have some difficulty understanding why do we have to extract a bigger number of crayons. Most of them think that we can be lucky and extract right two green crayons. Anyway, a large number of pupils reach the solution, saying that to have certain that we pick two green crayons we have to extract 10 crayons, because if we are unlucky, we can extract, first the 8 reds and after that we only can extract the green ones. We also add another task to this problem and ask children to say how many times do we have to extract crayons, without looking inside de box, to pick two red crayons?