| Platinum 3문제 expand_more |
 5726 | Tickets | USACO 2021 December Platinum | 1 | 1 | 100.00% |
 5727 | Paired Up | USACO 2021 December Platinum | 0 | 12 | 0.00% |
 5728 | HILO | USACO 2021 December Platinum | 1 | 26 | 3.85% |
| Gold 3문제 expand_more |
 5403 | 토끼쌍 (Paired Up) | USACO 2021 December Gold | 1 | 2 | 50.00% |
| 5761 | HILO | USACO 2021 December Gold | 1 | 8 | 12.50% |
 5762 | Bracelet Crossings | USACO 2021 December Gold | 1 | 4 | 25.00% |
| Silver 3문제 expand_more |
| 5354 | 가까운 소가 이겨버림 (Closest Cow Wins) | USACO 2021 December Silver | 3 | 7 | 42.86% |
 5355 | 두 개의 헛간을 연결했더니 생긴 일 (Connecting Two Barns) | USACO 2021 December Silver | 3 | 5 | 60.00% |
| 5356 | 복잡한 간격 (Convoluted Intervals) | USACO 2021 December Silver | 2 | 2 | 100.00% |
| Bronze 3문제 expand_more |
 5350 | 굉장히 효율적인 에어컨 시스템 (Air Cownditioning) | USACO 2021 December Bronze | 12 | 27 | 44.44% |
 5351 | 외로운 사진 (Lonely Photo) | USACO 2021 December Bronze | 15 | 48 | 31.25% |
| 5352 | 집으로 가즈아 (Walking Home) | USACO 2021 December Bronze | 7 | 10 | 70.00% |
