IMO 2003 Shortlist

IMO 2003 Shortlist — 27 problems. Algebra (6) · Combinatorics (6) · Geometry (7) · Number Theory (8).

27 items

IMO 2003 Shortlist

27 problems · Source: IMO Compendium

Algebra

# Origin Problem
A1 USA Let aij, i = 1, 2, 3, j = 1, 2, 3, be real numbers such that aij
A2 AUS Find all nondecreasing functions f : R \toR such that
A3 GEO Consider pairs of sequences of positive real numbers a1 \geq
A4 IRE Let n be a positive integer and let x1 \leqx2 \leq\cdot \cdot \cdot \leqxn be
A5 KOR Let R+ be the set of all positive real numbers. Find all
A6 USA Let n be a positive integer and let (x1, . . . , xn), (y1, . . . , yn)

Combinatorics

# Origin Problem
C1 BRA Let A be a 101-element subset of the set S = {1, 2, . . . ,
C2 GEO Let D1, . . . , Dn be closed disks in the plane. (A closed disk
C3 LIT Let n \geq5 be a given integer. Determine the largest integer
C4 IRN Let x1, . . . , xn and y1, . . . , yn be real numbers. Let A =
C5 ROM Every point with integer coordinates in the plane is the
C6 SAF Let f(k) be the number of integers n that satisfy the following

Geometry

# Origin Problem
G1 FIN Let ABCD be a cyclic quadrilateral. Let P, Q, R be the
G2 GRE Three distinct points A, B, C are fixed on a line in this order.
G3 IND Let ABC be a triangle and let P be a point in its interior.
G4 ARM Let \Gamma1, \Gamma2, \Gamma3, \Gamma4 be distinct circles such that \Gamma1,…
G5 KOR Let ABC be an isosceles triangle with AC = BC, whose
G6 POL Each pair of opposite sides of a convex hexagon has the
G7 SAF Let ABC be a triangle with semiperimeter s and inradius

Number Theory

# Origin Problem
N1 POL Let m be a fixed integer greater than 1. The sequence
N2 USA Each positive integer a undergoes the following procedure in
N3 BUL Determine all pairs (a, b) of positive integers such that
N4 ROM Let b be an integer greater than 5. For each positive integer
N5 KOR An integer n is said to be good if |n| is not the square of
N6 FRA Let p be a prime number. Prove that there exists a prime
N7 BRA The sequence a0, a1, a2, . . . is defined as follows:
N8 IRN Let p be a prime number and let A be a set of positive integers