

1. How many solutions does x^{2}  [x^{2}] = (x  [x])^{2} have satisfying 1 ≤ x ≤ n?


2. Show that abc ≥ (a+bc)(b+ca)(c+ab) for positive reals a, b, c.


3. Show that there is a point P inside the quadrilateral ABCD such that the triangles PAB, PBC, PCD, PDA have equal area. Show that P must lie on one of the diagonals.


4. ABC is a triangle with AB = 33, AC = 21 and BC = m, an integer. There are points D, E on the sides AB, AC respectively such that AD = DE = EC = n, an integer. Find m.


5. Each point in a 12 x 12 array is colored red, white or blue. Show that it is always possible to find 4 points of the same color forming a rectangle with sides parallel to the sides of the array.


6. Show that (2a1) sin x + (1a) sin(1a)x ≥ 0 for 0 ≤ a ≤ 1 and 0 ≤ x ≤ π

