25 October 2025

• curprev 17:0317:03, 25 October 2025 Marshall huang talk contribs 12,886 bytes +84 →Solution 12 (approachable and easy)
• curprev 17:0217:02, 25 October 2025 Marshall huang talk contribs 12,802 bytes +329 →Solution 12 (approachable and easy)

4 September 2025

• curprev 13:1913:19, 4 September 2025 Pinotation talk contribs 12,473 bytes −1 →Solutions
• curprev 13:1813:18, 4 September 2025 Pinotation talk contribs 12,474 bytes −1 →Solution 1 (Competition Speed and No Summation Notation)
• curprev 13:1813:18, 4 September 2025 Pinotation talk contribs 12,475 bytes +804 No edit summary

29 November 2024

• curprev 14:0014:00, 29 November 2024 Bird-of-a-feather talk contribs 11,671 bytes +1,384 Added another solution to 2019 12B problem 13. My solution is very approachable, providing a simple view of the problem anyone could understand, and doesn't require any memorization of infinite sum formulas.

30 October 2024

• curprev 23:2223:22, 30 October 2024 Arvinzhou talk contribs m 10,287 bytes −2 →Solution 1

14 July 2024

• curprev 20:5720:57, 14 July 2024 Goldroman talk contribs 10,289 bytes −617 →Solution 12 (a little bit like Archimedes's Cheese Argument): coincidence, just like solution 11 (if i'm wrong, sorry, and plz correct me)
• curprev 20:5620:56, 14 July 2024 Goldroman talk contribs 10,906 bytes −676 →Solution 11 (This method might be a coincidence)
• curprev 20:5120:51, 14 July 2024 Goldroman talk contribs 11,582 bytes −2 →Solution 1
• curprev 20:5120:51, 14 July 2024 Goldroman talk contribs 11,584 bytes −24 →Solution 1
• curprev 20:5120:51, 14 July 2024 Goldroman talk contribs 11,608 bytes +17 →Solution 1
• curprev 18:0618:06, 14 July 2024 Goldroman talk contribs 11,591 bytes +15 →Video Solution 2
• curprev 18:0518:05, 14 July 2024 Goldroman talk contribs 11,576 bytes −22 →Video Solution 1

25 March 2023

• curprev 23:2423:24, 25 March 2023 Eddy12597 talk contribs 11,598 bytes +617 →Solutions

8 November 2022

• curprev 22:4222:42, 8 November 2022 Russellk talk contribs 10,981 bytes +275 →Solution 11 (This method might be a coincidence)

4 November 2022

• curprev 03:4503:45, 4 November 2022 Pi is 3.14 talk contribs 10,706 bytes +16 →Video Solution 3

1 November 2022

• curprev 11:2311:23, 1 November 2022 Ethancui0529 talk contribs 10,690 bytes +16 →Solutions
• curprev 11:2311:23, 1 November 2022 Ethancui0529 talk contribs 10,674 bytes +385 →Solutions

16 October 2022

• curprev 12:4012:40, 16 October 2022 Nl008 talk contribs 10,289 bytes +8 →Solution 10
• curprev 12:4012:40, 16 October 2022 Nl008 talk contribs 10,281 bytes +591 →Solutions

8 June 2022

• curprev 23:2823:28, 8 June 2022 Sugar rush talk contribs 9,690 bytes +65 No edit summary
• curprev 23:2023:20, 8 June 2022 Erics son07 talk contribs 9,625 bytes +729 →Solution 1

3 October 2021

• curprev 08:1508:15, 3 October 2021 Asops talk contribs 8,896 bytes +695 No edit summary

25 April 2021

• curprev 09:1009:10, 25 April 2021 Bakedpotato66 talk contribs m 8,201 bytes +74 Compilation of all Video Solutions
• curprev 09:0909:09, 25 April 2021 Bakedpotato66 talk contribs m 8,127 bytes −73 Compilation of all Video Solutions

11 February 2021

• curprev 14:3014:30, 11 February 2021 Ogbooger talk contribs 8,200 bytes −59 No edit summary

17 January 2021

• curprev 20:5520:55, 17 January 2021 Pi is 3.14 talk contribs 8,259 bytes +73 →Video Solution 2

10 January 2021

• curprev 14:2514:25, 10 January 2021 Anmol04 talk contribs m 8,186 bytes +11 latex fix
• curprev 14:2414:24, 10 January 2021 Anmol04 talk contribs m 8,175 bytes +181 latex fix

26 September 2020

• curprev 01:1701:17, 26 September 2020 Icematrix talk contribs m 7,994 bytes +69 No edit summary

22 April 2020

• curprev 19:4719:47, 22 April 2020 Ericshi1685 talk contribs m 7,925 bytes +10 →Solution 8
• curprev 19:4519:45, 22 April 2020 Ericshi1685 talk contribs 7,915 bytes +54 →Solution 8
• curprev 19:4319:43, 22 April 2020 Ericshi1685 talk contribs 7,861 bytes +7 →Solution 8
• curprev 19:4319:43, 22 April 2020 Ericshi1685 talk contribs 7,854 bytes +397 →Solution 8
• curprev 19:4119:41, 22 April 2020 Ericshi1685 talk contribs 7,457 bytes +1,146 →Solution 7

20 April 2020

• curprev 08:5108:51, 20 April 2020 Grantstar talk contribs m 6,311 bytes +1 →Solution 3

7 February 2020

• curprev 15:0915:09, 7 February 2020 Fidgetboss 4000 talk contribs m 6,310 bytes +17 yeet

14 January 2020

• curprev 20:2520:25, 14 January 2020 Ogbooger talk contribs 6,293 bytes +1,045 No edit summary

12 January 2020

• curprev 16:4516:45, 12 January 2020 Shurong.ge talk contribs 5,248 bytes +30 →Solution 1

23 December 2019

• curprev 12:4312:43, 23 December 2019 J20080109 talk contribs m 5,218 bytes −18 →Solution 4
• curprev 12:4312:43, 23 December 2019 J20080109 talk contribs m 5,236 bytes −23 →Solution 3 (Summations)

13 December 2019

• curprev 23:5623:56, 13 December 2019 Bjhhar talk contribs 5,259 bytes +3 No edit summary
• curprev 23:5223:52, 13 December 2019 Bjhhar talk contribs 5,256 bytes −84 →Solution 6
• curprev 23:4723:47, 13 December 2019 Bjhhar talk contribs 5,340 bytes 0 →Solution 6
• curprev 23:4723:47, 13 December 2019 Bjhhar talk contribs m 5,340 bytes 0 →Solution 6
• curprev 23:4623:46, 13 December 2019 Bjhhar talk contribs m 5,340 bytes −2 →Solution 6
• curprev 23:4523:45, 13 December 2019 Bjhhar talk contribs 5,342 bytes +16 No edit summary
• curprev 23:4423:44, 13 December 2019 Bjhhar talk contribs 5,326 bytes +14 →Solution 6
• curprev 23:4323:43, 13 December 2019 Bjhhar talk contribs 5,312 bytes +20 →Solution 6