solve a cool problem and explore a new idea every week! A new problem and the solution to last week’s problem will be posted here every week. Currently, the Problem of the Week is on hold. In the meantime, PoTW #31 has an indefinite submission period: solve these three problems featured on math t-shirts!


Current PoTW: Week of X/X/2022 PoTW #X
Click here to submit a solution to this week’s PoTW!
Solution to last week’s PoTW:
Problems archive:
3/4/2022 PoTW #30: CMU Helicopter
2/18/2022 PoTW #29: Locus Practice
1/28/2022 PoTW #28: moving points (this is clickbait)
1/21/2022 PoTW #27: Wait. It’s coordinates? It always has been…
1/14/2022 PoTW #26: positive integers only
1/7/2022 PoTW #25: Double Factorial Sum
12/31/2021 PoTW #24: Iranian brain teaser
12/17/2021 PoTW #23: Adventures on the 9-point Circle, part 1
12/3/2021 PoTW #22: Cool Ellipse problem
11/26/2021 PoTW #21: Contrived Turkey
11/11/2021 PoTW #19: WELCOME BACK: AMC SEASON (:
9/25/2021 PoTW #18: AMC Week 1
9/16/2021 PoTW #17: 777 (part 2)
9/2/2021 PoTW #15: two practice alg problems
8/26/2021 PoTW #14: Factor Fest
8/19/2021 PoTW #13: Welcome to Math Team Airlines
8/12/2021 PoTW #12: Greatest Divisor
7/29/2021 PoTW #10: Graveling Graphs
7/22/2021 PoTW #9: It’s Coming Rome
7/1/2021 PoTW #6: Plushee Paradise
6/17/2021 PoTW #4: Phun Physics Phridays
6/10/2021 PoTW #3: The Sweetest Strawberry
6/3/2021 PoTW #2: Catalan Craziness
5/27/2021 PoTW #1: Vexing Hexagon
Solutions archive:
all solutions try to cover a variety of different approaches. sometimes solutions include more in-depth expositions into how a more general problem solving technique applies to the specific problem solution. solutions featuring these more detailed expositions are denoted with *.
1/14/2022 PoTW #26: positive integers only (solution)
1/7/2022 PoTW #25: Double Factorial Sum (solution)
12/31/2021 PoTW #24: Iranian Brain Teaser (solution)
12/17/2021 PoTW #23: Adventures on the 9-Point circle, part 1 (solution)
*12/3/2021 PoTW #22: Cool Ellipse Problem (solution) — ellipse properties (solvers: Jeffrey Chen, Jack Chen)
11/26/2021 PoTW #21: Contrived Turkey (solution)
*11/19/2021 PoTW #20: Poly Fib (solution) — theory of finite differences
11/11/2021 PoTW #19: WELCOME BACK: AMC SEASON (: (solution)
9/25/2021 PoTW #18: AMC Week 1 (solution)
9/16/2021 PoTW #17: 777 Pt. 2 (solution) (solvers: Jeffrey Chen, Jaden Chen)
9/9/2021 PoTW #16: 777 (solution) (solvers: Faizaan Siddique, Shaurya Agrawal, Jaden Chen, Benjamin Chen)
9/2/2021 PoTW #15: two practice alg problems (solution) (solvers: Jeffrey Chen)
8/26/2021 PoTW #14: Factor Fest (solution)
8/19/2021 PoTW #13: Welcome to Math Team Airlines (solution) (solvers: Faizaan Siddique, Brady Rivkin, Benjamin Chen, Anonymous, Anonymous)
8/12/2021 PoTW #12: Greatest Divisor (solution) (solvers: Faizaan Siddique)
8/5/2021 PoTW #11: OhMo (solution)
7/29/2021 PoTW #10: Graveling Graphs (solution) (solvers: Benjamin Chen)
7/22/2021 PoTW #9: It’s Coming Rome (solution)
*7/15/2021 PoTW #8: Oh Titu… (solution) — titu’s favorite factoring trick
*7/8/2021 PoTW #7: Blame Jack (solution) — harmonic quadrilaterals, mixtilinear incircles
7/1/2021 PoTW #6: Plushee Paradise (solution)
6/24/2021 PoTW #5: Algebra?? (solution)
6/17/2021 PoTW #4: Phun Physics Phridays (solution) (solvers: Jack Chen)
6/10/2021 PoTW #3: The Sweetest Strawberry (solution) (solvers: Jack Chen)
*6/3/2021 PoTW #2: Catalan Craziness (solution) — catalan numbers and generalizations
*5/27/2021 PoTW #1: Vexing Hexagon (solution) — power of a point (solvers: Jessica He, Jack Chen)
For hints or other inquiries about the PoTW, email: andliu22@students.d125.org