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The current in this river is the fastest in the center. Which path will get the ferry across the river in the least time?

When we connect some of the corners of these squares, a quadrilateral is formed. Can you find its area?

Every positive integer can be broken down into powers of two. Can you spot the shortcut to a special kind of sum?

Sometimes, we can rearrange the numbers in a grid so that every row and column has the same sum. Instead, could we make this sum by replacing numbers with 0s?

Successfully pulling off the tablecloth trick can require a lot of trial and error, spilt drinks, and broken glass. Can you master it a smarter way?

In a tracing puzzle, you canâ€™t lift your writing tool or go over a segment twice. This triangle is impossible, but is tracing it impossible, too?

Similar triangles can often hide in unexpected places. Could they help with this challenge?

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