You have 12 balls and each ball is numbered differently from 1 to 12. They are randomly placed into two bags so each contains six numbered balls as shown below:
- Red bag: 2, 3, 4, 6, 9, 11
- Blue bag: 1, 5, 7, 8, 10, 12
You then move a ball from the red bag to the blue bag. The total of the seven balls in the blue bag is now double the total of the five balls left in the red bag.
Which ball did you move from the red bag to the blue bag?
The 7puzzle Challenge
The playing board of the 7puzzle game is a 7-by-7 grid of 49 different numbers, ranging from 2 up to 84.
The 4th & 6th rows contain the following fourteen numbers:
3 5 10 12 18 20 32 33 35 44 49 54 56 60
How many pairs of numbers have a difference of 12?
Answers can be found here.
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