IMO 1984 Longlist

IMO 1984 Longlist — 48 problems.

48 items

IMO 1984 Longlist

48 problems · Source: IMO Compendium

Problem Origin Statement
AUS1 AUS The fraction
AUS2 AUS Given a regular convex 2m-sided polygon P, show that there is
AUS3 AUS The opposite sides of the reentrant hexagon AFBDCE in-
BEL4 BEL Given a triangle ABC, three equilateral triangles AEB, BFC,
BEL5 BEL For a real number x, let [x] denote the greatest integer not
BEL6 BEL Let P, Q, R be the polynomials with real or complex coefficients
BUL7 BUL Prove that for any natural number n, the number
BUL8 BUL In the plane of a given triangle A1A2A3 determine (with proof)
BUL9 BUL The circle inscribed in the triangle A1A2A3 is tangent to
BUL10 BUL Assume that the bisecting plane of the dihedral angle at edge
CAN15 CAN Consider all the sums of the form
FRA18 FRA Let c be the inscribed circle of the triangle ABC, d a line tan-
FRA19 FRA Let ABC be an isosceles triangle with right angle at point A.
FRG21 FRG (1) Start with a white balls and b black balls.
FRG23 FRG A 2 \times 2 \times 12 box fixed in space is to be filled with twenty-four
GBR26 GBR A cylindrical container has height 6 cm and radius 4 cm. It
GBR27 GBR The function f(n) is defined on the nonnegative integers n by:
GBR28 GBR A “number triangle” (tnk) (0 \leqk \leqn) is defined by tn,0 =
GDR29 GDR Let Sn = {1, . . . , n} and let f be a function that maps every
GDR30 GDR Decide whether it is possible to color the 1984 natural numbers
LUX31 LUX Let f1(x) = x3 +a1x2 +b1x+c1 = 0 be an equation with three
MON34 MON One country has n cities and every two of them are linked by a
MON35 MON Prove that there exist distinct natural numbers m1, m2, . . . ,
MON36 MON The set {1, 2, . . ., 49} is divided into three subsets. Prove that
MOR37 MOR Denote by [x] the greatest integer not exceeding x. For all
MOR38 MOR Determine all continuous functions f such that
MOR39 MOR Let ABC be an isosceles triangle, AB = AC, \angleA = 20◦. Let
NET41 NET Determine positive integers p, q, and r such that the diagonal
NET42 NET Triangle ABC is given for which BC = AC + 1
POL45 POL Let X be an arbitrary nonempty set contained in the plane and
ROM46 ROM Let (an)n\geq1 and (bn)n\geq1 be two sequences of natural numbers
ROM48 ROM Let ABC be a triangle with interior angle bisectors AA1,
ROM49 ROM Let n > 1 and xi \inR for i = 1, . . . , n. Set Sk = xk
SPA51 SPA Two cyclists leave simultaneously a point P in a circular run-
SPA52 SPA Construct a scalene triangle such that
SPA53 SPA Find a sequence of natural numbers ai such that ai = i+4
SPA54 SPA Let P be a convex planar polygon with equal angles. Let
SPA55 SPA Let a, b, c be natural numbers such that a+b+c = 2pq(p30+q30),
SWE56 SWE Let a, b, c be nonnegative integers such that a \leqb \leqc, 2b ̸=
SWE57 SWE Let a, b, c, d be a permutation of the numbers 1, 9, 8, 4 and let
SWE58 SWE Let (an)\infty
USA59 USA Determine the smallest positive integer m such that 529n +m\cdot
USA61 USA A fair coin is tossed repeatedly until there is a run of an odd
USA62 USA From a point P exterior to a circle K, two rays are drawn
USS64 USS For a matrix (pij) of the format m \times n with real entries, set
USS65 USS A tetrahedron is inscribed in a sphere of radius 1 such that the
USS67 USS With the medians of an acute-angled triangle another triangle is
USS68 USS In the Martian language every finite sequence of letters of