Hard problems

Classical problem collections, in each book's order. Green is solved, red is tried. Under each number, ✓ counts the players who solved it and ✕ everyone's failed attempts.

Xianji Wuku (1629): Corners

Chapter 1 Problems 2–49

  1. 2
  2. 3
  3. 4
  4. 5
  5. 7
  6. 8
  7. 9
  8. 10
  9. 11
  10. 12
  11. 13
  12. 14
  13. 15
  14. 16
  15. 17
  16. 18
  17. 19
  18. 20
  19. 21
  20. 22
  21. 23
  22. 24
  23. 25
  24. 26
  25. 27
  26. 28
  27. 29
  28. 30
  29. 31
  30. 32
  31. 33
  32. 34
  33. 36
  34. 37
  35. 38
  36. 39
  37. 40
  38. 41
  39. 42
  40. 43
  41. 44
  42. 45
  43. 46
  44. 47
  45. 48
  46. 49

Chapter 2 Problems 50–61

  1. 50
  2. 51
  3. 52
  4. 53
  5. 54
  6. 55
  7. 57
  8. 58
  9. 59
  10. 60
  11. 61

Chapter 3 Problems 64–65

  1. 64
  2. 65

Chapter 4 Problems 66–80

  1. 66
  2. 67
  3. 68
  4. 69
  5. 70
  6. 71
  7. 72
  8. 73
  9. 74
  10. 75
  11. 77
  12. 78
  13. 79
  14. 80

Chapter 5 Problems 81–84

  1. 81
  2. 82
  3. 83
  4. 84

Chapter 6 Problems 85–87

  1. 85
  2. 86
  3. 87

Chapter 7 Problems 88–96

  1. 88
  2. 89
  3. 90
  4. 91
  5. 92
  6. 93
  7. 94
  8. 95
  9. 96

Chapter 8 Problems 97–107

  1. 97
  2. 98
  3. 99
  4. 100
  5. 102
  6. 103
  7. 104
  8. 105
  9. 106
  10. 107

Chapter 9 Problems 108–114

  1. 108
  2. 109
  3. 110
  4. 111
  5. 112
  6. 113
  7. 114

Chapter 10 Problems 122–123

  1. 122
  2. 123

Chapter 11 Problems 124–125

  1. 124
  2. 125

Chapter 12 Problems 127–138

  1. 127
  2. 128
  3. 131
  4. 132
  5. 133
  6. 134
  7. 135
  8. 136
  9. 137
  10. 138

Chapter 13 Problems 139–142

  1. 139
  2. 140
  3. 141
  4. 142

Chapter 14 Problem 144

  1. 144

Chapter 15 Problems 145–148

  1. 145
  2. 146
  3. 147
  4. 148

Chapter 16 Problems 150–162

  1. 150
  2. 151
  3. 152
  4. 153
  5. 154
  6. 155
  7. 156
  8. 159
  9. 160
  10. 161
  11. 162

Chapter 17 Problems 163–192

  1. 163
  2. 164
  3. 166
  4. 167
  5. 168
  6. 169
  7. 170
  8. 171
  9. 172
  10. 173
  11. 174
  12. 175
  13. 176
  14. 177
  15. 178
  16. 179
  17. 180
  18. 181
  19. 182
  20. 183
  21. 185
  22. 186
  23. 187
  24. 188
  25. 189
  26. 190
  27. 191
  28. 192

Chapter 18 Problems 193–203

  1. 193
  2. 194
  3. 195
  4. 196
  5. 197
  6. 198
  7. 199
  8. 201
  9. 203