## 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

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

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

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

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

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

SolveQuestion 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

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

SolveQuestion 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

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

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

SolveQuestion 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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