Art of Problem Solving

Art of Problem Solving

Math texts, online classes, and more
for students in grades 5-12.

Visit AoPS Online ‚

Books for Grades 5-12 Online Courses

Engaging math books and online learning
for students ages 6-13.

Visit Beast Academy ‚

Books for Ages 6-13 Beast Academy Online

Small live classes for advanced math
and language arts learners in grades 2-12.

Visit AoPS Academy ‚

Find a Physical Campus Visit the Virtual Campus

Class Schedule Recommendations Olympiad Courses Free Sessions

AoPS Curriculum Beast Academy Online Books Recommendations Other Books & Gear All Products Gift Certificates

Forums Contests Search Help

math training & tools Alcumus Videos For the Win! MATHCOUNTS Trainer AoPS Practice Contests AoPS Wiki LaTeX TeXeR MIT PRIMES/CrowdMath Keep Learning All Ten

contests on aops Practice Math Contests

news AoPS Blog Webinars

view all 0

During AMC 10A/12A testing, the AoPS Wiki is in read-only mode and no edits can be made.

Resources Aops Wiki 2021 AMC 12A Problems/Problem 4: Revision history

Page

ArticleDiscussionReadView sourceView history

Toolbox

Recent changesRandom pageHelpWhat links hereAtomSpecial pages

Search

2021 AMC 12A Problems/Problem 4: Revision history

View logs for this page

Filter revisionsExpandCollapse

To date:

Tag filter:

Invert selection

Diff selection: Mark the radio buttons of the revisions to compare and hit enter or the button at the bottom.
Legend: (cur) = difference with latest revision, (prev) = difference with preceding revision, m = minor edit.

(newest | oldest) View (newer 50 | older 50) (20 | 50 | 100 | 250 | 500)

15 July 2025

curprev 08:1408:14, 15 July 2025 Pomfun talk contribs m 6,449 bytes −167 Video was no longer available
curprev 08:1408:14, 15 July 2025 Pomfun talk contribs m 6,616 bytes −89 Video was no longer available

28 October 2022

curprev 21:4521:45, 28 October 2022 MRENTHUSIASM talk contribs m 6,705 bytes +1 →Video Solution by OmegaLearn(Using Logic to Eliminate Choices)
curprev 21:0021:00, 28 October 2022 Pi is 3.14 talk contribs m 6,704 bytes +13 →Video Solution (Using Logic to Eliminate Choices)

5 January 2022

curprev 03:0903:09, 5 January 2022 MRENTHUSIASM talk contribs m 6,691 bytes 0 No edit summary

4 September 2021

curprev 06:5706:57, 4 September 2021 MRENTHUSIASM talk contribs 6,691 bytes −259 Cleaned up the page by combining solutions. Also, I credited abhinavg0627 as the primary author of Sol 1.1. Let me know if anyone is unhappy about it.

22 August 2021

curprev 23:2823:28, 22 August 2021 MRENTHUSIASM talk contribs m 6,950 bytes −4 →Solution 2 (Comprehensive Explanation Using Arrows): Changed title.

3 July 2021

curprev 19:3219:32, 3 July 2021 Thelearningroyal talk contribs m 6,954 bytes +71 No edit summary

26 May 2021

curprev 19:0119:01, 26 May 2021 MRENTHUSIASM talk contribs m 6,883 bytes 0 →Video Solution (Using logic to eliminate choices)
curprev 17:5617:56, 26 May 2021 MRENTHUSIASM talk contribs m 6,883 bytes −2 →Video Solution 6

14 May 2021

curprev 15:5415:54, 14 May 2021 MRENTHUSIASM talk contribs 6,885 bytes +2 →Solution 3 (Process of Elimination): Changed Sol 2 to Sol 2.1 to be more specific.

23 April 2021

curprev 08:1808:18, 23 April 2021 MRENTHUSIASM talk contribs m 6,883 bytes −2 →Solution 2.2 (Rigorous)

18 April 2021

curprev 13:5013:50, 18 April 2021 MRENTHUSIASM talk contribs m 6,885 bytes +385 Added "Remark" in 2.2

14 April 2021

curprev 19:3719:37, 14 April 2021 MRENTHUSIASM talk contribs m 6,500 bytes 0 →Solution 2 (Comprehensive Explanation Using Arrows)
curprev 19:2419:24, 14 April 2021 MRENTHUSIASM talk contribs m 6,500 bytes −10 →Solution 2 (Comprehensive Explanation Using Arrows)
curprev 19:0019:00, 14 April 2021 MRENTHUSIASM talk contribs m 6,510 bytes +37 →Solution 2.2 (Rigorous)
curprev 18:4918:49, 14 April 2021 MRENTHUSIASM talk contribs m 6,473 bytes 0 →Solution 2.1 (Intuitive)
curprev 18:4418:44, 14 April 2021 MRENTHUSIASM talk contribs m 6,473 bytes +98 →Solution 2 (Comprehensive Explanation Using Arrows)
curprev 18:3918:39, 14 April 2021 MRENTHUSIASM talk contribs 6,375 bytes +14 →Solution 2.2 (Rigorous)
curprev 18:3218:32, 14 April 2021 MRENTHUSIASM talk contribs m 6,361 bytes −1 →Solution 2.2 (Rigorous)
curprev 18:3118:31, 14 April 2021 MRENTHUSIASM talk contribs m 6,362 bytes +2 →Solution 2.2 (Rigorous)
curprev 18:2718:27, 14 April 2021 MRENTHUSIASM talk contribs m 6,360 bytes +86 →Solution 2.2 (Rigorous)
curprev 17:1517:15, 14 April 2021 MRENTHUSIASM talk contribs m 6,274 bytes +20 →Solution 2.2 (Rigorous)
curprev 12:5312:53, 14 April 2021 MRENTHUSIASM talk contribs m 6,254 bytes +5 →Solution 4 (Rigorous)
curprev 12:5212:52, 14 April 2021 MRENTHUSIASM talk contribs m 6,249 bytes +26 →Solution 4 (Rigorous)
curprev 12:4712:47, 14 April 2021 MRENTHUSIASM talk contribs m 6,223 bytes +2 →Solution 2.2 (Rigorous)
curprev 12:3912:39, 14 April 2021 MRENTHUSIASM talk contribs m 6,221 bytes +3 →Solution 2 (Comprehensive Explanation Using Arrows)
curprev 11:4911:49, 14 April 2021 MRENTHUSIASM talk contribs m 6,218 bytes −2 →Solution 2.2 (Rigor)
curprev 11:3511:35, 14 April 2021 MRENTHUSIASM talk contribs 6,220 bytes +135 →Solution 2 (Comprehensive Explanation Using Arrows)
curprev 11:1311:13, 14 April 2021 Peace09 talk contribs 6,085 bytes +11 →Solution 4 (Rigorous)
curprev 11:1311:13, 14 April 2021 Peace09 talk contribs 6,074 bytes −86 →Solution 4 (Rigorous)
curprev 10:5310:53, 14 April 2021 MRENTHUSIASM talk contribs 6,160 bytes +106 →Solution 2 (Comprehensive Explanation Using Arrows): Added in braces.
curprev 10:4510:45, 14 April 2021 MRENTHUSIASM talk contribs m 6,054 bytes +100 →Solution 2 (Comprehensive Explanation Using Arrows)
curprev 09:5009:50, 14 April 2021 MRENTHUSIASM talk contribs m 5,954 bytes +13 →Solution 2 (Explanation Using Arrows)
curprev 09:4309:43, 14 April 2021 MRENTHUSIASM talk contribs 5,941 bytes +555 →Solution 2 (Explanation Using Arrows)
curprev 09:1509:15, 14 April 2021 MRENTHUSIASM talk contribs m 5,386 bytes −1 →Solution 2 (Explanation Using Arrows)
curprev 08:5908:59, 14 April 2021 MRENTHUSIASM talk contribs 5,387 bytes −155 Undo revision 151483 by MRENTHUSIASM (talk) Tag: Undo
curprev 07:2507:25, 14 April 2021 MRENTHUSIASM talk contribs 5,542 bytes +155 →Solution 2 (Explanation Using Arrows)

13 April 2021

curprev 23:5823:58, 13 April 2021 MRENTHUSIASM talk contribs m 5,387 bytes +30 →Solution 2 (Explanation Using Arrows)
curprev 23:5723:57, 13 April 2021 MRENTHUSIASM talk contribs 5,357 bytes +23 →Solution 2 (Explains Solution 1 Using Arrows): Reformatted.
curprev 23:2023:20, 13 April 2021 MRENTHUSIASM talk contribs m 5,334 bytes −2 No edit summary
curprev 23:1023:10, 13 April 2021 MRENTHUSIASM talk contribs 5,336 bytes −158 →Solution 4 (Rigorous): Adjusted the code so it renders.
curprev 22:2122:21, 13 April 2021 Peace09 talk contribs 5,494 bytes +139 →Solution 4 (Rigorous)
curprev 22:2022:20, 13 April 2021 Peace09 talk contribs 5,355 bytes +2,242 No edit summary

12 April 2021

curprev 19:3219:32, 12 April 2021 MRENTHUSIASM talk contribs m 3,113 bytes −42 →Solution 2 (Explains Solution 1 Using Arrows)

1 April 2021

curprev 19:5519:55, 1 April 2021 MRENTHUSIASM talk contribs m 3,155 bytes +10 →Problem: Improved layout.

25 March 2021

curprev 18:3418:34, 25 March 2021 MRENTHUSIASM talk contribs m 3,145 bytes −21 →Solution 2 (Explains Solution 1 Using Arrows)
curprev 18:3318:33, 25 March 2021 MRENTHUSIASM talk contribs m 3,166 bytes +5 →Solution 2 (Explains Solution 1 Using Arrows)

15 March 2021

curprev 23:5723:57, 15 March 2021 MRENTHUSIASM talk contribs m 3,161 bytes +25 →Solution 3: Titled the solution.

14 March 2021

curprev 23:1223:12, 14 March 2021 MRENTHUSIASM talk contribs m 3,136 bytes +17 →Solution 3: Solution 2's arrows explain POE.

(newest | oldest) View (newer 50 | older 50) (20 | 50 | 100 | 250 | 500)

Retrieved from "https://artofproblemsolving.com/wiki/index.php?title=2021_AMC_12A_Problems/Problem_4"

Art of Problem Solving is an
ACS WASC Accredited School

aops programs

About

Site Info

follow us

Subscribe for news and updates

© 2025 AoPS Incorporated

© 2025 Art of Problem Solving

About Us • Contact Us • Terms • Privacy

Copyright © 2025 Art of Problem Solving

Something appears to not have loaded correctly.

Click to refresh.