IMO 1972 Shortlist

IMO 1972 Shortlist — 12 problems. 12 problems.

12 items

IMO 1972 Shortlist

12 problems · Source: IMO Compendium

Problems

# Origin Problem
1 BUL Let f and ϕ be real functions defined on the set R satisfying
2 CZS We are given 3n points A1, A2, . . . , A3n in the plane, no three
3 CZS Let x1, x2, . . . , xn be real numbers satisfying x1+x2+\cdot \cdot \cdot+xn =
4 GDR Let n1, n2 be positive integers. Consider in a plane E two dis-
5 GDR Prove the following assertion: The four altitudes of a tetrahe-
6 GDR Show that for any n ̸\equiv0 (mod 10) there exists a multiple of
7 GBR (a) A plane \pi passes through the vertex O of the regular
8 GBR Let m and n be nonnegative integers. Prove that m!n!(m+
9 NET Find all solutions in positive real numbers xi (i =
10 NET Prove that for each n \geq4 every cyclic quadrilateral can
11 NET Consider a sequence of circles K1, K2, K3, K4, . . . of radii
12 USS A set of 10 positive integers is given such that the decimal