MathDB
Problems
Contests
National and Regional Contests
USA Contests
USA - Middle School Tournaments
LMT
2023 LMT Fall
19
19
Part of
2023 LMT Fall
Problems
(1)
2023 Fall LMT Speed p19 - 6 points on circle
Source:
3/2/2024
Evin picks distinct points
A
,
B
,
C
,
D
,
E
A, B, C, D, E
A
,
B
,
C
,
D
,
E
, and
F
F
F
on a circle. What is the probability that there are exactly two intersections among the line segments
A
B
AB
A
B
,
C
D
CD
C
D
, and
E
F
EF
EF
?Proposed by Evin Liang
combinatorics
geometry