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Two and One
Terry and Ali are playing a game with three balls. Is it fair that Terry wins when the middle ball is red?
Age 5 to 7
Challenge Level
Well done Annie (who didn't give her school) and Rukmini from Dowanhill Primary who sent well explained solutions. Rukmini says:
The totals which were odd were: 1, 3, 3, and 5. There were 4 odd-total dominoes. Erik can only choose these 4 dominoes.The totals which were even were: 2, 4, 2, 4, and 6. There were 5
even-total dominoes. Sanjay can only choose these 5 dominoes.
In the next game Erik can only choose a multiple of 3, which are: 6, 3 and 3. So Erik can choose 3 dominoes.
In this game, Erik can choose only 4 and Sanjay can choose 5. Sanjay has
more, and that's not fair.
In the next game Erik can only choose a multiple of 3, which are: 6, 3 and 3. So Erik can choose 3 dominoes.
And Sanjay can choose 6, so it's not fair
again. Sanjay can pick up the most dominoes.
Children from WHS pointed out that it cannot be fair because there are only 9 dominoes and this does not divide equally by two. A very good point, well done.
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NRICH is part of the family of activities in the Millennium Mathematics Project.
NRICH is part of the family of activities in the Millennium Mathematics Project.