## Brain Teaser

Question How many four-digit numbers can we create by rearranging digits of 2021? All four of the digits must be used exactly once

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Question You drop a stack of three balls. The bottom ball is the heaviest, with the middle ball much lighter and the top ball much

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Question Jaz makes circular necklaces by stringing black and gold beads together. She wants to count how many different necklaces

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Question At a university, the portraits of its 50 presidents line a hallway of the student center. Every year, 50 students pull th

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Question Your goal is to measure out 7 liters of water. You have one empty 12-liter container, and you may choose one other contai

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Question There are x regular polygons, all with n sides of length 1 arranged in a row as the triangles, squares, and pentagons are

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Question In a grassy field, a goat is tethered by a rope with length 6 to the corner of a rectangular shed with side lengths 4 and

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Question Look at the program above:   Imagine running this program 21 times, with each of the integers from -10 to 10 as the

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Question Only one-digit numbers can start with a zero. If every letter corresponds to a different digit, what is A+B+C+D? 5 9 19 2

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Question The mobile shown is balanced. Karen is quite happy with her perfectly balanced mobile.   Karen’s friend Juli i

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Question The yellow pentagon is inside of a rectangle. What is the yellow-shaded area? 52 68 72 74 80

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Question The outer figure is a square and the line from each vertex bisects its opposite side. What is the area of the central whi

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