Registration
What is Školjka?
Školjka is a web archive of math problems, a tool intended for primary and high school students training for math contests. It contains thousands of problems from various math contests in recent two decades.
Why Školjka?
Školjka supports searching by categories and difficulty, allowing students to quickly find the exact problems they are interested in. Likewise, Školjka can be helpful to mentors and teachers for preparing lectures.
Selected competitions
Recently added tasks
1 year, 7 months
1 year, 7 months
Recent activities:
20. May
21:48
19:41
13:32
19. May
23:00
12:10
17. May
14:41
15. May
Rješenje
16:17
10:01
14. May
21:38
13. May
19:35
11. May
08:59
10. May
22:29
16:46
9. May
21:19
19:09
16:59
7. May
20:22
5. May
20:20
4. May
16:35
30. April
23:40
23:15
29. April
18:22
26. April
21:24
25. April
14:34
24. April
22:53
23. April
20:04
16:32
13:54
13:03
12:54
Školjka
, pri čemu je
prost, a
prirodan broj za koje vrijedi
,
i
sa središtima
,
,
i polumjerima duljina
,
,
, redom međusobno se dodiruju izvana tako da je
diralište kružnica
diralište kružnica
diralište kružnica
.