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Puzzle 1
What number comes next in the sequence:
1 · 2 · 3 · 5 · 9 · 12 · ?
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Puzzle 2
What is the minimum number of queens required on a chessboard such that all squares are attacked?
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Puzzle 3
There are three houses, and three utilities: water, gas, and electricity.
Your task is to connect each house to all three utilities.
Therefore, each house will have three lines, and each utility will also have three lines.
However, you cannot cross lines! You cannot pass lines through houses or utilities. You cannot share lines.
Can you draw the 9 lines required?
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Puzzle 4
Can you make this equation correct by moving exactly one matchstick?
Note: this puzzle is not interactive, and the matchsticks cannot be moved. The matchstick layouts for each digit are:
