A new problem will be released soon.
Arf League
- Who is Cahit Arf? What is Arf League?
-
Info and Announcements
Info
✔ There are 132 problems and 82 key facts, waiting for math enthusiasts! Dear Math Enthusiasts,
Thanks for your interest in Arf League.
✔ Among 1.12 billion active websites, AhMath is now within the top 0.014862%, and we hope its position will get better soon. We try to serve the best for all of you.
✔ Please feel free to send your comments and suggestions to challenging-problems@ahmath.com and help us to promote this lovely activity by distributing the
Arf League Poster and the QR Code.
✔ Arf League is looking for new problem and/or key fact writers. If you are interested in writing challenging math problems and/or key facts, please contact us. We'll be glad to meet with new question writers.
hide this To submit your answers you need to log in.
If you are not a member of this page and if your name is not listed in the score tables, you need to sign up first. Otherwise, please read the following instructions given below!
hide this This is the place where you can find the most valuable Mathematical Olympiads books!
New pages from AhMath: Unordered Times Table, Unordered Divisibility Test, Bulls and Cows Game, Unique Bid Auction Game, and Guess My Country. Check them out!
Explore all your possibilities. Udemy online courses on sale from $11.99- New Problem
- Previous Problems
- Score Tables
- Books, Key Facts, etc.
- HQTs
- Testimonials
- Donate / Become a Patron
Format of the items of the selection menu: Problem Order, Problem Code (Difficulty Level). Red problems have a difficulty level of less than 0.75, thus, as an example, a 0.18 means only 18% of all answers submitted are correct.
Futured Math Enthusiasts
is solved firstly by
Mohamed Karamany
7611
by Hanlee Wong
Long Jumper
Marathon Runner
since 11.11.2019
80009
Score Table - Math Enthusiasts (only the first 100)
Score depends on number of correct answers and number of trials.
- FS stands for First Solver. For each problem, there is a first solver. Each time you solve a problem as the first person your FS score increases by one.
- SF stands for Solution Files. Some of the Math Enthusiasts sends solutions to the problems. This is to promote their valuable contribution to the Arf League.
- SP stands for Sniper. You can get this badge if and only if you do not miss any problem in your first try and solve them correctly. Only snipers have the potential to get the full score.
- UT stands for User Type. "MT" is for Math Teacher and "S" is for Student.
hide this Please submit your country to be listed in this table!
Order | Score | # of Correct Answers | Names | Badges | Country | |||
---|---|---|---|---|---|---|---|---|
FS | SF | SP | UT | |||||
1. | 097.73 | 130 | Angelo M. Velasquez | 130 | 47 | S | Philippines | |
2. | 083.69 | 127 | Lee Csek | 127 | 2 | China | ||
3. | 083.63 | 117 | Lisa Sauermann | 117 | 2 | S | Germany | |
4. | 083.05 | 123 | Zhuo Qun Song | 123 | 2 | S | Canada | |
5. | 076.71 | 122 | Daryll Ko | 122 | 0 | S | Philippines | |
6. | 076.48 | 115 | Isaiah James de Dios Maling | 115 | 34 | MT | Philippines | |
7. | 075.22 | 128 | Caed Mark Medul Mendoza | 128 | 112 | MT | Philippines | |
8. | 060.31 | 94 | Jeffrey Robles | 94 | 5 | Philippines | ||
9. | 056.20 | 103 | Reygan Medina Dionisio | 103 | 2 | MT | Philippines | |
10. | 052.13 | 92 | Richard Phillip Dimaala Fernandez | 92 | 90 | MT | Philippines | |
11. | 050.76 | 67 | Lilanie Monique Torilla | 67 | 55 | ❂ | S | Philippines |
12. | 049.96 | 84 | Jereco Dela Pena | 84 | 0 | MT | Philippines | |
13. | 047.77 | 65 | Sumet Ketsri | 65 | 67 | Thailand | ||
14. | 045.46 | 71 | Amirul Faiz Abdul Muthalib | 71 | 0 | MT | Malaysia | |
15. | 042.43 | 69 | Radu Bogo | 69 | 45 | Romania | ||
16. | 041.86 | 59 | Hanlee Wong | 59 | 63 | S | Singapore | |
17. | 041.02 | 62 | Kurara Chibana | 62 | 0 | S | Japan | |
18. | 040.91 | 54 | Willie Revillame Wowowin | 54 | 0 | ❂ | Philippines | |
19. | 040.63 | 63 | Russel J. Galanido | 63 | 30 | S | South Korea | |
20. | 035.87 | 66 | Mertkan Simsek | 66 | 0 | MT | Turkey | |
21. | 035.82 | 79 | Christian Paul C. Patawaran | 79 | 1 | S | Philippines | |
22. | 035.06 | 54 | Marvin Cato | 51 | 30 | MT | Philippines | |
23. | 031.73 | 66 | Fujiwara Toneri | 66 | 6 | S | Japan | |
24. | 031.31 | 62 | Arcy Leann | 62 | 15 | S | Philippines | |
25. | 030.57 | 52 | Law Tik Shun | 52 | 0 | MT | Hong Kong | |
26. | 028.61 | 48 | Nixon Balandra | 48 | 46 | MT | Philippines | |
27. | 028.32 | 54 | Randy Orton | 54 | 0 | United States of America | ||
28. | 028.12 | 60 | Rindell Mabunga | 60 | 31 | S | Philippines | |
29. | 027.15 | 49 | Raffy Salazar | 49 | 0 | S | Philippines | |
30. | 026.52 | 35 | Arjun Singh Rajawat | 35 | 4 | ❂ | S | India |
31. | 025.57 | 45 | Rik Smoody | 45 | 0 | MT | United States of America | |
32. | 025.47 | 41 | Jacob Sabido | 41 | 5 | S | Philippines | |
33. | 022.74 | 41 | Darwin Ojera | 41 | 22 | MT | Philippines | |
34. | 020.88 | 41 | Joselito Torculas | 41 | 26 | Philippines | ||
35. | 020.18 | 57 | Roenz Joshlee Timbol | 57 | 1 | S | Philippines | |
36. | 020.04 | 36 | Lim Jing Ren | 36 | 0 | S | Malaysia | |
37. | 019.70 | 26 | Alea Astrea | 26 | 0 | ❂ | S | Philippines |
38. | 019.48 | 30 | echo gabata | 30 | 0 | Vietnam | ||
39. | 019.25 | 36 | Lourenz Miguel Paras | 36 | 0 | S | Philippines | |
40. | 017.44 | 41 | Hanz U. Baga | 41 | 73 | S | Philippines | |
41. | 017.07 | 26 | Kuba Helsztynski | 26 | 0 | MT | Poland | |
42. | 015.06 | 26 | Sajib Kumar Chowdhury | 26 | 0 | S | Bangladesh | |
43. | 014.39 | 19 | Lenard Guillermo | 19 | 2 | ❂ | S | Philippines |
44. | 013.77 | 20 | Gluttony | 20 | 0 | Philippines | ||
45. | 013.64 | 30 | Angelo Bungcaras Magdaong | 30 | 1 | MT | Philippines | |
46. | 013.27 | 29 | Joseph Rodelas | 29 | 0 | S | Philippines | |
47. | 012.63 | 20 | Mark Alvero | 20 | 0 | MT | Philippines | |
48. | 012.49 | 26 | Norwyn Nicholson Kah | 26 | 38 | S | Philippines | |
49. | 012.46 | 25 | Jhepoy Dizon | 25 | 0 | S | Philippines | |
50. | 012.43 | 19 | Ramon Villota | 19 | 0 | S | Philippines | |
51. | 011.75 | 32 | Daniel James Molina | 32 | 1 | S | Philippines | |
52. | 011.22 | 20 | Ralph Macarasig | 20 | 0 | S | Philippines | |
53. | 011.16 | 18 | Ric Tura Jr | 18 | 21 | S | Philippines | |
54. | 010.67 | 18 | Maureen Jordan | 18 | 1 | Singapore | ||
55. | 010.61 | 14 | John Albert A. Reyes | 14 | 6 | ❂ | S | Philippines |
56. | 009.95 | 17 | Nheil Ignacio | 17 | 8 | S | Philippines | |
57. | 009.65 | 22 | Hanelet Santos | 22 | 15 | S | Philippines | |
58. | 009.54 | 23 | Kumar Ayush | 23 | 1 | S | India | |
59. | 009.14 | 28 | Mark Kenneth Dairo | 28 | 26 | S | Philippines | |
60. | 009.12 | 17 | Ibrahim Demir | 17 | 1 | MT | Turkey | |
61. | 008.77 | 18 | Francis Gerard Magtibay | 18 | 0 | S | Philippines | |
62. | 008.66 | 20 | Charles Dwight M. Pelaez | 20 | 8 | S | Philippines | |
63. | 008.55 | 19 | Bikram Chohan | 19 | 5 | S | India | |
64. | 008.33 | 11 | Melga Sonio | 11 | 0 | ❂ | S | Philippines |
65. | 008.29 | 19 | angelo magdaong | 19 | 0 | MT | Philippines | |
66. | 008.00 | 13 | Poetri Sonya Tarabunga | 13 | 0 | S | Indonesia | |
67. | 007.42 | 14 | Ewen Goisot | 14 | 17 | France | ||
68. | 007.05 | 11 | Max Wong | 11 | 0 | S | Hong Kong | |
69. | 007.00 | 43 | Kimi No Nawa | 43 | 166 | S | Japan | |
70. | 006.96 | 21 | Christian Daang | 21 | 25 | S | Philippines | |
71. | 006.75 | 14 | Angelu G. Leynes | 14 | 0 | S | Philippines | |
72. | 006.55 | 11 | Mark Elis Espiridion | 11 | 0 | Philippines | ||
73. | 006.26 | 17 | Stefano Ongari | 17 | 0 | S | Italy | |
74. | 005.82 | 13 | Chris Norman Algo | 13 | 10 | S | Philippines | |
75. | 005.30 | 7 | Adrian Pilotos Burgos | 7 | 0 | ❂ | Philippines | |
76. | 004.55 | 6 | Yavuz Selim Koseoglu | 6 | 0 | ❂ | S | Turkey |
77. | 004.55 | 6 | Mahmut Cemrek | 6 | 0 | ❂ | Turkey | |
78. | 004.55 | 6 | John Gamal Aziz Attia | 6 | 1 | ❂ | S | Egypt |
79. | 004.55 | 6 | Jade N. Mijares | 6 | 0 | ❂ | S | Philippines |
80. | 003.66 | 13 | Aljun Emperado | 13 | 3 | S | Philippines | |
81. | 003.25 | 27 | Keedgwh | 27 | 0 | India | ||
82. | 003.03 | 6 | Liu Chen | 6 | 0 | China | ||
83. | 003.03 | 6 | Kevin Durant | 6 | 0 | S | Turkey | |
84. | 003.03 | 6 | John Lester Tan | 6 | 0 | S | Philippines | |
85. | 003.03 | 4 | Vaibhav Priyadarshi | 4 | 0 | ❂ | S | India |
86. | 003.03 | 4 | Βαρελάς Γεώρ𝛾ιος | 4 | 0 | ❂ | Greece | |
87. | 002.71 | 5 | Kot Behemot | 5 | 0 | MT | United States of America | |
88. | 002.42 | 4 | Saket Singh Rajawat | 4 | 1 | S | India | |
89. | 002.42 | 4 | Bryant Ularte | 4 | 0 | MT | Philippines | |
90. | 002.27 | 3 | Jomari Mama | 3 | 0 | ❂ | MT | Philippines |
91. | 002.27 | 3 | Gerald M. Pascua | 3 | 0 | ❂ | Philippines | |
92. | 001.89 | 5 | Leandro Dar Juan | 5 | 0 | S | Philippines | |
93. | 001.89 | 5 | Ian Galang | 5 | 0 | S | Philippines | |
94. | 001.73 | 4 | Smahi Abdeslem | 4 | 4 | S | Algeria | |
95. | 001.73 | 4 | Elijah Evangelista | 4 | 0 | S | Palau | |
96. | 001.52 | 6 | David Paul | 6 | 0 | S | Philippines | |
97. | 001.52 | 4 | Luke Robitaille | 3 | 1 | S | United States of America | |
98. | 001.52 | 2 | James Harden | 2 | 0 | ❂ | S | Philippines |
99. | 001.36 | 3 | John Kenneth Vito Cruz | 3 | 0 | S | Philippines | |
100. | 001.10 | 4 | Mark David Mortel Dela Cruz | 4 | 0 | S | Philippines |
hide this All problems are solved 3699 times.
Score Table - Countries
NOTE: Countries are listed according to their first answer submit dates.
Country | # of Correct Answers | # of Trials | Performance |
---|---|---|---|
Egypt | 7 | 7 | 100% |
Philippines | 2459 | 3540 | 69.46% |
Turkey | 111 | 156 | 71.15% |
Greece | 4 | 4 | 100% |
South Korea | 63 | 74 | 85.14% |
Thailand | 87 | 107 | 81.31% |
Indonesia | 13 | 16 | 81.25% |
Japan | 184 | 396 | 46.46% |
Malaysia | 107 | 133 | 80.45% |
Peru | 1 | 1 | 100% |
Algeria | 4 | 7 | 57.14% |
India | 151 | 340 | 44.41% |
Canada | 127 | 145 | 87.59% |
Italy | 17 | 35 | 48.57% |
Romania | 71 | 90 | 78.89% |
United States of America | 117 | 167 | 70.06% |
Germany | 118 | 125 | 94.4% |
France | 14 | 20 | 70% |
Poland | 26 | 30 | 86.67% |
Hong Kong | 64 | 82 | 78.05% |
Vietnam | 30 | 35 | 85.71% |
Iran | 2 | 8 | 25% |
Nigeria | 1 | 1 | 100% |
China | 133 | 155 | 85.81% |
Singapore | 77 | 86 | 89.53% |
Bangladesh | 26 | 34 | 76.47% |
Palau | 4 | 7 | 57.14% |
Argentina | 0 | 2 | 0% |
-
Worked Solutions to the Problems
Solutions to all Challenging Math Problems are ready!
If you want to get the pdf of all the questions with solutions please do the payment by using the paypal button given on the left. For more documents and info about olympiads, please click Olympiads.
-
Online Problem Solver
Key Facts
-
1. Key Fact |Tags: product, rational, number, irrational
-
2. Key Fact |Tags: fraction, lowest term, numerator, denominator, relatively prime
-
3. Key Fact |Tags: square, even, integer, divisibility
-
4. Key Fact |Tags: square, odd, integer, divisibility
-
5. Key Fact |Tags: product, perfect square, consecutive numbers
-
6. Key Fact |Tags: divisibility
-
7. Key Fact |Tags: identity, factorial
-
8. Key Fact |Tags: identity
-
9. Key Fact |Tags: identity
-
10. Key Fact |Tags: identity
-
11. Key Fact |Tags: factorial, inequality
-
12. Key Fact |Tags: identity
-
13. Key Fact |Tags: identity
-
14. Key Fact |Tags: Sophie-Germain, identity
-
15. Key Fact |Tags: identity
-
16. Key Fact |Tags: identity, factorization
-
17. Key Fact |Tags: identity, factorization
-
18. Key Fact |Tags: identity
-
19. Key Fact |Tags: composite number
-
20. Key Fact |Tags: prime number, definition
-
21. Key Fact |Tags: prime number, composite number, 1
-
22. Key Fact |Tags: prime number, composite number, 1
-
23. Key Fact |Tags: prime number, even
-
24. Key Fact |Tags: prime number
-
25. Key Fact |Tags: prime numbers
-
26. Key Fact |Tags: prime factorization
-
27. Key Fact |Tags: prime number, composite number
-
28. Key Fact |Tags: Wilson's Theorem
-
29. Key Fact |Tags: Bertrand's Postulate, prime number
-
30. Key Fact |Tags: Bonse's Inequality, prime numbers
-
31. Key Fact |Tags: prime, divisor
-
32. Key Fact |Tags: divisibility, square, odd, integer
-
33. Key Fact |Tags: divisibility
-
34. Key Fact |Tags: divisibility
-
35. Key Fact |Tags: product, consecutive, integer, divisibility
-
36. Key Fact |Tags: divisibility
-
37. Key Fact |Tags: binomial expansion
-
38. Key Fact |Tags: binomial expansion, number of terms
-
39. Key Fact |Tags: identity
-
40. Key Fact |Tags: identity
-
41. Key Fact |Tags: identity
-
42. Key Fact |Tags: identity
-
43. Key Fact |Tags: identity
-
44. Key Fact |Tags: chessboard, square
-
45. Key Fact |Tags: arithmetic mean, real numbers
-
46. Key Fact |Tags: geometric mean, real numbers
-
47. Key Fact |Tags: arithmetic mean, geometric mean, inequality
-
48. Key Fact |Tags: harmonic mean, real numbers
-
49. Key Fact |Tags: arithmetic mean, harmonic mean, inequality
-
50. Key Fact |Tags: inequality
-
51. Key Fact |Tags: inequality
-
52. Key Fact |Tags: inequality
-
53. Key Fact |Tags: inequality, identity
-
54. Key Fact |Tags: inequality
-
55. Key Fact |Tags: inequality
-
56. Key Fact |Tags: inequality
-
57. Key Fact |Tags: inequality
-
58. Key Fact |Tags: inequality
-
59. Key Fact |Tags: inequality, identity
-
60. Key Fact |Tags: Cauchy–Schwarz, inequality
-
61. Key Fact |Tags: Chebyshev, inequality
-
62. Key Fact |Tags: line, intersection, parabola, abscissa, vertex, midpoint, line segment
-
63. Key Fact |Tags: De Moivre, formula
-
64. Key Fact |Tags: fibonacci, numbers
-
65. Key Fact |Tags: finite serie, finite sequence
-
66. Key Fact |Tags: infinite serie, infinite sequence
-
67. Key Fact |Tags: partial sum, series
-
68. Key Fact |Tags: sequence, partial sum, series, limit
-
69. Key Fact |Tags: sequence, partial sum, series, limit
-
70. Key Fact |Tags: series, sum
-
71. Key Fact |Tags: sum, infinite serie
-
72. Key Fact |Tags: relative error, measurement
-
73. Key Fact |Tags: angle, bisector, triangle
-
74. Key Fact |Tags: sum, exterior angles, convex, polygon
-
75. Key Fact |Tags: triangle, circle, greatest area, isosceles triangle
-
76. Key Fact |Tags: circle, plane, common tangent
-
77. Key Fact |Tags: lattice points, gcd, greatest common divisor
-
78. Key Fact |Tags: right triangle, median
-
79. Key Fact |Tags: minimal polynomial
-
80. Key Fact |Tags: british flag theorem, rectangle, geometry
-
81. Key Fact |Tags: pythagorean triple, triangle
-
82. Key Fact |Tags: primitive pythagorean triples, triangle
If you want to be a problem (or key fact) writer, please contact AhMath by sending an email to challenging-problems@ahmath.com.
Ahmet Arduc
Question Writer
Number of questions: 113Ahmet worked as a maths olympiad instructor for many years. He is the editor and co-author of the unpublished 484-page book “Mathematical Olympiad Preliminary Question Bank, with 1001 solved questions”. His students got high achievements in many local and national mathematical competitions.
Amirul Faiz Abdul Muthalib
Problem Writer
Number of problems: 10With over 5 years of hands-on, successful teaching experience, Amirul is an enthusiastic Pre-University Mathematics Lecturer in INTEC Education College, Malaysia. Being a versatile individual who love Maths, he has earned a Master’s Degree in Mechanical Engineering in Japan. He had opportunity to teach Maths in Japanese Syllabus for scholarship sponsored students who will further their study in KOSEN (National College of Technology in Japan). He also train some of his students for the National Olympiad every year.
İhsan Yücel
Problem Writer
Number of problems: 3Ihsan is currently in the thesis phase of his postgraduate education, which is about mathematics teaching education. He got some notable national and international achievements in various secondary school mathematics and project competitions. He’s an author of many scientific articles about mathematics in the quarterly magazine "Mathematical World". He’s the founder of Matematik Meraklısı, a website dedicated to Mathematics.
Richard Phillip Dimaala Fernandez
Problem Writer
Number of problems: 1Richard is an experienced math teacher in a Chinese school in the Philippines. He is a product of Philippine Normal University (National Center for Teacher Excellence). He trains students who compete in both local and international math competitions. He is a trainer in Mathematics Trainers' Guild, Philippines (MTG Philippines) and Metrobank-MTAP-DepEd Math Challenge (MMC). He is also a lecturer in one of the review centers specialized in university entrance examinations. He is also a Suken Test Passer (Mathematics Certification Institute of Japan).
You?
Subject?
Leave a Comment!
Please use the form below to send your general comments about Arf League. All fields are required!
It's a good way to practice maths and also the site encourages you to submit your answer with an accompanying solution. Participants can not just simply guess the answer or predict what will be the answer based on the given, they need to know and understand the topic. Also this refrains participants to just simply ask the answer from other people. So the method was excellent and people will definitely learn many things about math.
- Rindell Mabunga / Philippines
I want to say my deepest gratitude in creating this website. The questions are not the typical type and not normally taught to non-mathematical major degrees. I really hope that you'll continue your mission and vision in creating this site, as this serves as a platform to enhance our mathematical skills. Hoping for the best good luck!!!
- Russel J. Galanido / South Korea
I see AhMath as the one encouraging self-paced learning or practice in solving math problems. It does not put me into any kind of pressure like requiring myself to be the first one to solve the problems correctly and giving answers with a limited time. Also, it gives me excitement for the next problems to solve as well as for the appearance of my name on the list of the people who submitted the correct solutions and answers for those math problems. Overall, it gives me confidence to be better in math.
Thank you for everything, AhMath.- Marvin Cato / Philippines
I knew AhMath from a facebook group, "Math Enthusiasts Quiz Group", that I just joined a few weeks ago. Then I found that there are the "challenging math problems" here that refresh my Math skill.
I like many ideas on this website, the word "Math Enthusiasts" exactly describes what I'm and it makes me recall the feeling about Math when I was young, it was fun and exciting!
I like the motto "Real than i, rational than n", it's playing in my head and I'm still doubt about its meaning :-D
There is no time constraint for solving the problems so we can think about the solutions in the different ways. Sometimes the new solutions reveal the beauty of Math and that only happens when we have time to think about other solutions.
Thank you the creator and moderator of this website, especially Ahmet Arduc, who brings me back to the feeling of fun and exciting with his creative problems.- Sumet Ketsri / Thailand
Ahmath is basically a great site. The problems are really challenging and mind boggling. I really like the way that the Math enthusiasts should show the solution as well for each problem. You need to learn on your own. This site greatly help me improve my Math skills and writing solutions as well. Thank you much Ahmath for an amazing job. More power and God bless. "Train HARD, win EASY. Train Easy, win HARD". Hoping you all the best out there. Just continue on your aim to help the students as well as the non-students to further enhance their math skills. God bless and More power AHMATH FTW!!!
- Isaiah James de Dios Maling / Philippines
I want to thank sir Ahmet Arduc for creating this wonderful site AhMath. The "Challenging Math Problems" are really challenging. Most of the problems are math problems that you can't normally encounter in school. You can solve the problems in different ways. You can find some beautiful patterns while solving these problems. The problems are addictive especially the problems created by sir Ahmet. It brings me back the way i feel when i was young, the excitement and having fun when solving math problems. I'm always excited to see my name on the list of people who solved the problem correctly! I can say that I am really a Math Enthusiast now and I improved a lot with my mathematical skills. I also like that there is no time limit in solving the problems. You can solve the problems when you are not busy or you are in the mood to solve. Thank you Ahmath, I hope you'll continue to improve this site and help us to be better. Hoping you all the best, God bless!
- Caed Mark Medul Mendoza / Philippines
I am not one of the most gifted math wizards from my country. Through AhMath, I am able to hone my skills and at least par with them, although I am still far from their prowess. Some simple questions are masked to seem difficult and all problems that I have solved felt satisfying knowing that I was able to use, display, and hone my skills.
- Fujiwara Toneri / Japan
This is a good website for math enthusiast who wants to challenge their math ability. Thanks for questions that push us to think differently and of course to learn new things.. More powers and God Bless.
- Reygan Dionisio / Philippines
Most Active Modules
Explore all your possibilities. Udemy online courses on sale from $11.99 Go to top of page