8th Mexican Mathematical Olympiad Problems 1994A1. The sequence 1, 2, 4, 5, 7, 9 ,10, 12, 14, 16, 17, ... is formed as follows. First we take one odd number, then two even numbers, then three odd numbers, then four even numbers, and so on. Find the number in the sequence which is closest to 1994.
7th Mexican Mathematical Olympiad Problems 1993A1. ABC is a triangle with ∠A = 90o. Take E such that the triangle AEC is outside ABC and AE = CE and ∠AEC = 90o. Similarly, take D so that ADB is outside ABC and similar to AEC. O is the midpoint of BC. Let the lines OD and EC meet at D', and the lines OE and BD meet at E'. Find area DED'E' in terms of the sides...