2017 AMC 12B — Practice Log
Quick reflections and timing notes.
Q1–Q23: all correct ✅
Q22: time sink ⏳
Q24–Q25: not answered ❌
Notable Questions
- #13: Took me a while; need to keep practicing Burnside's lemma/technique. (note to self: revisit topic & drill)
- #22: Became a time sink. Pause sooner; sketch structure, estimate difficulty, and decide quickly whether to skip.
- #24: Didn’t understand the question—unclear how to set up the average. Re-read carefully; translate wording to variables first.
- #25: Ran out of time.
Process & Timing Notes
- Not enough time at the end—was able to draw the diagram but didn’t complete the setup.
- For average/setup questions: define variables immediately, write the equation before computing.
- When a problem starts ballooning (>3–4 minutes without structure), mark and move.
Follow-Up Plan
- 22: Not sure how to express √abi cleanly.
Couldn’t manage complex numbers or split the area into 4 pieces. - 25: Was able to get the powers of 10 and simplify, but not the final casework step.
- 20: Tried coordinate bash but didn’t realize AOBX is cyclic.
- 21: Very close, but made a mistake in casework.
- 22: No idea how to estimate.
- 24: Confusing — unsure how to approach.
- 25: Imaginary numbers solution was smart.
Also homothety solution was smart too.
Monday, September 1, 2025
9/1/2025 Student Reflection Note from H
2018 AMC 12A Notes 🎉
😊 Only 2 Wrong — Great Job!
Wrong
Right
15, 16, 17, 18, 19, 20, 21, 23, 24
8/31/2015 Student reflection notes from H
2019 AMC 12B Notes
Problems 20–25 → Wrong
Problems 15–19, 23 → Right
Saturday, August 23, 2025
8/23/2025 student reflection notes from H ～ Welcome back to the States.
2019 AMC 12A – Reflection Log
Quick notes on misses, themes, and time sinks.
Incorrect
- #22. Problem and Solutions
- #24. Found all prime exceptions but missed 4 — Problem and Solutions
- #25. Got after hint → need work on angle chasing in cyclic quadrilaterals — Problem and Solutions
Correct
Problems solved:
#15
#16
#17
#18
#19
#20
#21
#23
- #17 → learn Newton's Sums
- #23 → algebra took a long time.
Next Steps
- Drill Newton’s Sums identities; derive first 3–4 power sums using Vieta.
- Re-check prime-exception logic; include 2 and 4 in prime-exception checklist.
- Daily 10-min cyclic quadrilateral angle-chasing (use Ptolemy, equal angles, arc marks).
- Practice pacing to avoid #17-style time sinks; enforce a 2-minute “move on” rule.
- Algebra endurance reps (substitution, factoring patterns), especially for de-jangling #23-type problems.
Tuesday, August 19, 2025
8/19/2025 student reflection notes from H
2020 AMC 12B Reflections
Wrong Questions
- Q19: Not sure how to approach. My casework method was too complicated.
- Q21: Solution made sense. I made the substitution
u = 70n + 50, but couldn’t expand it properly. - Q23: Saw that
n = 2,n = 3worked, but I couldn’t eliminate later cases ofn ≥ 4. - Q25: Solution seemed easy, but I didn’t see the graphical method earlier. I have to get better at identifying that.
Correct Questions
- Q15: Solved correctly.
- Q16: Solved correctly.
- Q17: Solved correctly.
- Q18: Solved correctly.
- Q20: Solved correctly.
- Q22: Solved correctly.
- Q24: Solved correctly.
Friday, August 15, 2025
8/15/2025 2020 AMC 12 A student reflection notes from H while in India
2020 AMC 12A Log
Wrong
- Q18 – Tried other equation → could not solve
- Q23 – Hard casework (I could guess if correct, more of a check)
- Q24 – Weird set, specialized translations in geometric problem
- Q25 – Really hard Q. Required graphing + adaptation for 2Ï€ trap but not confident/solid
Right
- Q15
- Q16
- Q17
- Q19
- Q20
- Q21
- Q22
Thursday, August 7, 2025
8/6/2025 2014 AMC 12 B student reflection notes from H while in India :)
2014 AMC 12B Log
Correct:
- 15
- 16
- 17
- 18 – took time
- 19
- 20
- 22 – time-sink
- 24
- 25
Wrong:
- 21 – struggled with too many variables
- 23 – no idea how to approach
Friday, August 1, 2025
8/1/2025 2014 AMC 12 A student reflection notes from H
2014 AMC 12A — Log
Incorrect Problems
Problem 20
- The lengths are totally random
- Why are they rotated?
Problem 23
- No comment
Problem 25
- Weird parabola
- Not sure how to solve
Correct Problems
- Problem 15
- Problem 16
- Problem 17
- Problem 18 — Took time
- Problem 19
- Problem 21 — Hard b/c of endpoint → took a while; Quick inside a hard transformation
- Problem 22 — Took time
- Problem 24 — Graphed it to solve
Monday, July 28, 2025
7/28/2025 2013 AMC 12 B student reflection notes from H
2013 AMC 12B LOG
Incorrect Problems
- Problem 23 – No idea how to start
- Problem 24 – Almost got it through angle chasing
- Problem 25 – Very close, right idea but missed a few cases
Correct Problems
Problems solved correctly: 15, 16, 17, 18, 19, 20, 21, 22
- Problem 17 – Should learn Cauchy-Schwarz
- Problem 20 – Ran out of time
Friday, July 25, 2025
7/25/2025 H 2013 12 A reflection notes
2013 AMC 12A Log
Incorrect Problems
- Problem 20 – Totally confused
- Problem 24 – Right idea but casework had too many cases
- Problem 25 – No idea how to start
Correct Problems
Problems solved correctly: 15, 16, 17, 18, 19, 21, 22, 23
- Problem 16 – Took too long
- Problem 23 – Angle chasing was hard
- Had to look at answer choices
Saturday, July 12, 2025
7/12/2025 2012 AMC 12A H reflection notes
2012 AMC 12 A Reflection Notes
Correct Answers: Questions 15–21
- Questions: 15, 16, 17, 18, 19, 20, 21
- Note on #16: Took time on one question using the Law of Cosines
Unanswered but Attempted: Questions 22, 23
- Q22 & Q23:
- Able to solve with help from solution
- Need to improve:
- Organized counting of objects
- 3D visualization skills
- Q23 Additional Note:
- Not able to solve during the test
- Watched a video solution afterward—it made sense, but I wouldn’t have made that connection under time pressure
Unanswered: Questions 24, 25
- Q24:
- Not able to compare exponents correctly
- Had to look at the solution to understand
- It was a complicated question
- Q25:
- Unable to solve even after reviewing the solution
- Gaps in understanding—don’t think I could have arrived at that solution myself
- Struggled with 3D visualization and drawing the necessary graph
Tuesday, July 8, 2025
7/8/2025 2011 AMC 12B H reflection notes
Q16 → Wrong due to silly mistake
Skipped Q20
- Time-sink solution requires heavy observation and quick identification.
- Involves quick use of inscribed angles and arcs.
Q25 → Not enough time
Was not able to solve; did not understand substitution of
n → n-k in the solution + solution video.
Redo!
Q24 Notes:
- Easy algebra but looked difficult at first.
- Just required extra time to complete — able to solve afterwards.
Q15, Q17, Q18, Q19, Q21, Q22, Q23 → Correct
- Q17: Online solution took a long time
- I had the fastest solution : the solution was first finding g(f(x)) = 10x-1, then subbing in the 1 to get h_1(1)=9, then continuously subbing 9 back into 10x-1 so it becomes 9, 89, 899, 8999….
- Q19: Took a long time
- Found faster solution but took time to get to it: this was a least upper bound question for the slope which hits the next lattice point. If I had the answers, it would have been easier to substitute them back into and find which one would work, but I had hidden the answers. What I did next was find a few of the closest points to 102, 50 which the slope would first intersect and the slope would be as close to 1/2 as possible. After testing a few values in the form of (n/1)/(2n+1) and (n+1)/(2n) which give values close to 1/2, 50/99 was the least of these.
