Question The semicircle has the right triangle’s hypotenuse as its diameter. The radius of the quarter-circle equals a leg l

Question The title of Brilliant’s Problem Solver of the Year has been narrowed down to five candidates: Katherine J., Muhamm

Question Gracie plays a game where she spins arrows around the two circles below. The circle on the left is divided into four sect

Question In this game of Nim, Abdi and Suri are playing with one heap of 11 stones and another heap of 9 stones. The game is playe

Question To celebrate the end of exams, three couples met for a dinner. They’re about to take seats at a round table for six

Question This figure includes 20 line segments. Using these rules:   you can start at any intersection on the figure, you can

Question Ada, Bella, Colette, and Delia are about to stand in a row, and Bella and Colette want to stand next to each other. What

Question Clara left the house and realized that she forgot her keys. She asked her sister Daria to throw them from the balcony at

Question You are trying to decide if you should play the following game:   You are given $5 for free. You keep flipping a fai

Question Jerome has two empty containers: a 16-liter and an 18-liter container.   He needs to measure out exactly 10 liters i

Question Matilda’s aquarium contains ten fish. For a science project, she randomly takes out one fish, marks it, and puts it

Question The Minotaur is imprisoned at the center of a maze called the Labyrinth. To pass the time, he’s taken up a hobby: e