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2 x 2 = 2 + 2 - math puzzle
| Two times two is equal to two and two. But are there more number pairs for which the sum of the numbers is is equal to the product of the numbers? The numbers may be different. |
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Chess-board - math puzzle
| How many different squares are located on a chess-board? |
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Long rope - math puzzle
| Suppose you have an enormous long rope. You place this rope on the soil along the equator, such that the rope forms a circle around the earth. After you have finished this big job, you increase the length of the rope by one meter. How far from the soil do yo have to attach the rope to make again a circle around the equator? Assume that the earth is a perfect sphere, without mountains etc. |
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