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Logical Thinking Riddle

Logical Thinking Riddle - 9 April

I have 100 coins in my wallet.

What is the minimum number of coin(s) needed to be placed in a flat floor , to make sure each coin touched exactly three other coins.

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  1. 4

    3 placed flat on the table in a triangle(touching each other) and put the fourth one on top of them in the middle

  2. If the coins are to be laid flat it is not possible, since no end coin can touch more than 2 coins and any center coin will touch more than 3. If they can be stacked then a triangle of coins with one in the center on top, or 4. The 100 coins is a red herring.

    1. Don't line them up. Take seven coins of the same denomination. Place one in the center and place a ring of six coins around it.

      Each coin will touch three others.

    2. But the central coin is touching 6 right?

  3. the answer is three hundred

  4. 5 put one coin below