2019 AMC12B P17--Recursive Sequence Interval Estimation

 2019 AMC12B P16--Complex Numbers & Equilateral Triangle

 2019 AMC12B P15-- Frog Jumping Probability

 2019 AMC12B P14--Area Between Circle and Semicircles

 2019 AMC12B P13--Products of Distinct Divisors

 2019 AMC12B P12--Probability with Colored Balls

 2019 AMC12B P11--Isosceles Triangle and Equal Perimeter Conditions

 2019 AMC 12B P10--Unordered Pairs of Edges in a Cube

 2019 AMC 12B P9--Counting Paths in a Graph

 2019 AMC 12B P8-- Counting Integer-Sided Triangles

 2019 AMC 12B P6--Points Satisfying Perimeter & Area Conditions

 2019 AMC 12B P5--Locus and Equidistance Conditions

 2019 AMC 12B P4--Sum of Digits via Algebraic Equation

 2019 AMC 12B P3--Rigid Transformations on the Coordinate Plane

 2019 AMC 12B P2--Counterexample in Logic

 2019 AMC 12B P1--Volume Ratio Basics

 2018 F=ma EXAM A P25--Combining Independent Measurements

 2018 F=ma EXAM A P24--Rigid Rod + Mass: Axis Pivot Oscillation

 2018 F=ma EXAM A P23--Angular Acceleration on Sloped Ramp

 2018 F=ma EXAM A P22--Leak Rate vs Time in Sinking Boat

 2018 F=ma EXAM A P21--Rolling Ping-Pong Ball: Slip to Roll Transition

 2018 F=ma EXAM A P20-Energy Storage in Cut vs Whole Spring

 2018 F=ma EXAM A P19--Rain Pressure Changes: Density, Radius, Speed

 2018 F=ma EXAM A P18--Tension Difference in Vertical Circular Motion

 2018 F=ma EXAM A P17-- Shape of Sand Stream after Helicopter Turn

 2018 F=ma EXAM A P16--Coriolis Effect in Rotating Space Station

 2018 F=MA EXAM A P15-- Kinetic Energy Increase in Circular Orbit

 2018 F=MA EXAM A P14--Oscillation Periods in Tri-Rod Pendulu

 2018 F=MA EXAM A P13--Young’s Modulus via Tightrope Tension

 2018 F=MA EXAM A P12-- Uncertainty in Pendulum Experiment

 2018 F=MA EXAM A P11-- Half-Spring Frequency Doubling

 2018 F=MA EXAM A P10--Acceleration vs Time with Air Drag

 2018 F=MA EXAM A P9--Forces on a Rod Being Lifted by a Rope

 2018 F=ma EXAM B P8--Rolling Disk within a Hoop: Instantaneous Speed

 2018 F=ma EXAM B P7--Minimum Time for a to–b Maneuver with Braking

 2018 F=ma EXAM B P6--Crate Rolling Up a Ramp with Friction

 2018 F=ma EXAM B P5--Inclined Plane & Pulley Momentum Puzzle

 2018 F=ma EXAM A P4--

2018 F=ma EXAM A P4--Optimal Impulse Application in Orbit

Optimal Impulse Application in Orbit

 2018 F=ma EXAM B P3--Optimal Impulse Application in Orbit

 2018 F=ma EXAM B P2--Conservation Exceptions in Collision

 2018 F=ma EXAM A P1--Velocity Graph with Air Resistance

 2024AMC 12B P25--Symmetry of Rational Functions

 2024AMC 12B P24--Exploring the Disphenoid Mystery

 2024AMC 12B P23 SOL2--Elegant Identities in Action

 2024AMC 12B P23 SOL1--Trig Products Made Easy

 2024AMC 12B P22 SOL2--Counting Loops with Logic

 2024AMC 12B P22 SOL1--The Toothpick Puzzle Explained

 2024AMC 12B P21 SOL2--Sum of Squares the Smart Way

 2024AMC 12B P21 SOL1--Mastering the Recurrence Trick

 2024AMC 12B P20--Triangle Probability: Area Less Than Half?

 2024AMC 12B P19--Cyclic Quadrilateral: What’s the Shortest Diagonal?

 2024AMC 12B P18--Stacking Cards: When Will a Vertex Land on B?

 2024AMC 12B P17--System of Three: What’s the Value of ab + bc + ca?

 2024AMC 12B P16-- ProToken Distribution: What’s the Probability for Each Player?

 2024AMC 12B P15--Cubic Roots Product: A Surprising Value!

 2024AMC 12B P14--Arithmetic Grid: Can You Fill in the Missing Number?

 2024AMC 12B P13--Graph Symmetry: Where Is the Reflected Point?

 2024AMC 12B P12--Geometric Sequence: What’s the Smallest Possible b?

 2024AMC 12B P11--Base Trick: For Which b Is 2024\_b Divisible by 16?

 2024AMC 12B P10--Triangle Angles in Radians: Connecting α and β

 2024AMC 12B P9--Double Perfect Square Riddle: What’s the Unit Digit?

 2024AMC 12B P8--Logarithm Equation: How Many Angles Can You Find?

 Dialogues with Dr. Wang 7/7 Juntao’s Final Words

 Dialogues with Dr. Wang 6/7 Social Justice and Youth Responsibility A Message to the Next Generation

 Dialogues with Dr. Wang 5/7 The Global Trend of Democracy and the Meaning of Individual Action

 Dialogues with Dr. Wang 4/7 U.S. Education vs. Chinese Youth Development

 Dialogues with Dr. Wang 2/7 Freedom, Justice, and the Real Challenges Facing Chinese Society

 Dialogues with Dr. Wang 2/7China-U.S. Relations and Economic Prospects after Trump’s Re-election

 Dialogues with Dr. Wang Juntao 1/7 Juntao’s Story and the Era of China-U.S. Civilization Clash

 2024AMC 12B P7-- Vector Sum Parade: 2024 Points on a Hypotenuse

 2024AMC 12B P6-- Product of Three: The Least Positive Sum Game

 2024AMC 12B P5--Mean Mystery: How Many 6s Did You Remove?

 

2024AMC 12B P4--Factorial Showdown: What’s the Least n for 2024 Divisibility?

 2024AMC 12B P3--Minimal Number Puzzle: The Fewest Steps to 2024

 2024AMC 12B P2-- Path to the Top: Can You Solve This Mountain Hike Problem?

 2024AMC 12B P1--Quick Calculation Challenge: Can You Outsmart This Arithmetic?

 2024AMC 12A P25 SOL2--Systematic Enumeration: Filter Out the Solutions

 2024AMC 12A P25 SOL1--Symmetry Attack: Algebraic Perspective

 2024AMC 12A P24 SOL2--Using Formulas: Heron's Formula for the Win

 2024AMC 12A P24 SOL1- Parameter Hunt: Enumerating All Possibilities

 2024AMC 12A P23 SOL2--Smart Substitution: Plug and Play for Tangents

 2024AMC 12A P23 SOL1--Clever Identity: Transform and Conquer Tangents!

 2024AMC 12A P22--Combinatorics in Action: Counting the Loops

 2024AMC 12A P21 SOL2-- Formula Derivation: Summing Squares the Fast Way

 2024AMC 12A P21 SOL1--Sequence Recurrence: Huge Sum Challenge!

 2024AMC 12A P20--Triangle Probability: Less Than Half the Area?

 2024AMC 12A P19--Cyclic Quadrilateral Quest: The Shortest Diagonal

 2024AMC 12A P18--Card Stacking&Geometry Vertex Miracle

 2024AMC 12A P17--System of Three: Find ab + bc + ca

 2024AMC 12A P16--Token Distribution: What’s the Winning Probability?

 2024AMC 12A P15--Cubic Roots & Products: What’s the Value?

 2024AMC 12A P14--Arithmetic Array: Can You Crack the Grid?

 2024AMC 12A P13--Exponential Graph Symmetry: Reflected Points

 2024AMC 12A P12--Geometric Sequence Surprise: Least Possible Value

 2024AMC 12A P11-- Divisibility in Any Base: Base-b Number Tricks

 2024AMC 12A P10--Triangle Angle Radians: Relating α and β

 2024AMC 12A P8-- Trig Log Equation: How Many Angles?

 2024AMC 12A P7--Vector Parade in a Right Triangle

 2024AMC 12A P5--Mean Switcheroo: The Mystery of Disappearing 6s

 2024AMC 12A P3--Minimal Sum Challenge: How Few Numbers Do You Need?

 2024AMC 12A P2-- Mountain Hike Model: Linear System Puzzle

 2024AMC 12A P1--Arithmetic Tricks: Can You Outsmart This Calculation?

 2019B F=ma EXAM P25--Gravity Measurement: How to Minimize Your Uncertainty?

 2019B F=ma EXAM P24--Pulley Rope Acceleration: How Fast Does the End Move?

 2019B F=ma EXAM P23--Train Over Bumpy Track: How High Is Too High?

 2019B F=ma EXAM P22--Apple Bruise Test: How Much Pressure to Cause Damage?

 2019B F=ma EXAM P21--Freight Car and Falling Grain: Calculating the Normal Force!

 2019B F=ma EXAM P20--Up the Ramp, Down the Ramp: How Do Times Compare?

 2019B F=ma EXAM P19--Pendulum Acceleration: What’s the Real Curve?

 2019B F=ma EXAM P18--Race Car Timing: Which Uncertainty Matters Most?

 2019B F=ma EXAM P17--Disk vs. Hoop: Will It Return Home Too?

 2019B F=ma EXAM P16--Rolling Hoop: How Long Till It Comes Back?

 2019B F=ma EXAM P15--Air Resistance in a Swing: How Strong Is the Drag?

 2019B F=ma EXAM P14--Elastic Wall Bounce: Find the Launch Speed!

 2019B F=ma EXAM P13--Water Hose vs. Wall: What’s the New Splash Zone?

 2019B F=ma Exam P12--Planets Orbiting: Who Has More Energy and Momentum?

 2019B F=ma Exam P11-Cutting out a Circle:Moment of inertia Puzzle

 2019B F=ma Exam P10--Cart and Bowl: How Fast Does the Cart Go?

 2019B F=ma Exam P9--Board and Ball: How Much Force Keeps It Up?

 2019B F=ma Exam P8--Hand-Pressed Scale: What Does It Read?

 2019B F=ma Exam P7--Floating Boat in Trough: Which Wire Bears the Load?

 2019B F=ma Exam P6--Spinning Dust Cylinder: How Density Changes with Radius

 2019B F=ma Exam P5--Earth’s Gravity: What Does the Curve Look Like?

 2019B F=ma Exam P4--Colliding Masses: Gravitational Race!

 2019B F=ma Exam P3--Series Springs: Whose Energy Wins?

 2019B F=ma Exam P2--Floating Blocks: Can You Guess the Densities?

 2019B F=ma Exam P1--Friction on the Ramp: How Much Energy Disappears?

 2020 AMC 12B P25 SOL2 – The Final Boss (Elegant Finish)

 2020 AMC 12B P25 SOL1– The Final Boss. Can You Beat It? (Full Solution)

 2020 AMC 12B P24 SOL2--Expert’s Trick

 2020 AMC 12B P24 – 3 Concepts, 1 Problem, Zero Room for Error

 2020 AMC 12B P23 – Think You’re Good? Try This One

 2020 AMC 12B P22 SOL2-The Most Elegant Problem (Creative Approach)

 2020 AMC 12B P22 – The Most Elegant Problem of the Set (Standard Solution)

 2020 AMC 12B P21 SOL2 – This One Will Test Your Limits (Alternative Tactic)

 2020 AMC 12B P21 SOL1 – This One Will Test Your Limits (Classic Approach)

 2020 AMC 12B P20 – Trickiest Word Problem Yet

 2020 AMC 12B P19 – Beautiful Logic, Brutal Details

 2020 AMC 12B P18 – Where Most Give Up

 2020 AMC 12B P17 – The “Aha!” Moment You’ll Love

 2020 AMC 12B P16 – Time to Level Up!

 2020 AMC 12B P14 – One Small Misstep, Game Over

 2020 AMC 12B P13 – Clever Algebra in Disguise

 2020 AMC 12B P12 – Beautiful Symmetry or Sneaky Trick?