23 September 2020

• 01:0501:05, 23 September 2020 diff hist −35 2020 IMO Problems/Problem 6 No edit summary
• 01:0301:03, 23 September 2020 diff hist +623 N 2020 IMO Problems/Problem 6 Created page with "Problem 6. Prove that there exists a positive constant c such that the following statement is true: Consider an integer n > 1, and a set S of n points in the plane such that t..."
• 01:0201:02, 23 September 2020 diff hist +329 N 2020 IMO Problems/Problem 5 Created page with "Problem 5. A deck of n > 1 cards is given. A positive integer is written on each card. The deck has the property that the arithmetic mean of the numbers on each pair of cards..."
• 01:0201:02, 23 September 2020 diff hist +803 N 2020 IMO Problems/Problem 4 Created page with "Problem 4. There is an integer n > 1. There are n 2 stations on a slope of a mountain, all at different altitudes. Each of two cable car companies, A and B, operates k cable c..."
• 01:0101:01, 23 September 2020 diff hist +360 N 2020 IMO Problems/Problem 3 Created page with "Problem 3. There are 4n pebbles of weights 1, 2, 3, . . . , 4n. Each pebble is coloured in one of n colours and there are four pebbles of each colour. Show that we can arrange..."
• 01:0001:00, 23 September 2020 diff hist +9 2020 IMO Problems/Problem 2 No edit summary
• 00:5600:56, 23 September 2020 diff hist +139 N 2020 IMO Problems/Problem 2 Created page with "Problem 2. The real numbers a, b, c, d are such that a ≥ b ≥ c ≥ d > 0 and a + b + c + d = 1. Prove that (a+2b+3c+4d)<math>a^a</math>"
• 00:5500:55, 23 September 2020 diff hist +348 N 2020 IMO Problems/Problem 1 Created page with "Problem 1. Consider the convex quadrilateral ABCD. The point P is in the interior of ABCD. The following ratio equalities hold: ∠P AD : ∠P BA : ∠DP A = 1 : 2 : 3 = ∠CB..."