8th Iberoamerican Mathematical Olympiad Problems 1993

A1.  A palindrome is a positive integers which is unchanged if you reverse the order of its digits. For example, 23432. If all palindromes are written in increasing order, what possible prime values can the difference between successive palindromes take? A2.  Show that any convex polygon of area 1 is contained in some parallelogram of area 2. A3.