1. In this post, there are problems from Regional Mathematics Olympiad, RMO 2009. Try out these problems.
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  3. Let ABC be a triangle in which AB = AC and let I be its in-centre. Suppose BC = AB + AI. Find ∠BAC.
    Discussion
  4. Show that there is no integer a such that a^2-3a-19 is divisible by 289.
  5. Show that 3^{4008}+4^{2009} can be written as product of two positive integers each of which is larger than 2009^{182} .
  6. Find the sum of all 3-digit natural numbers which contain at least one odd digit and at least one even digit.
  7. A convex polygon \Gamma is such that the distance between any two vertices of \Gamma does not exceed 1.
    • Prove that the distance between any two points on the boundary of \Gamma does not exceed 1.
    • If X and Y are two distinct points inside \Gamma , prove that there exists a point Z on the boundary of \Gamma such that XZ+YZ \le 1 .
  8. In a book with page numbers from 1 to 100, some pages are torn off. The sum of the numbers on the remaining pages is 4949. How many pages are torn off?

Some Useful Links:

RMO 2002 Problem 2 – Fermat’s Last Theorem as a guessing tool– Video

Our Math Olympiad Program