MathDB
2018 Chile Classification / Qualifying NMO Juniors XXX

Source:

October 11, 2021
algebrageometrynumber theorycombinatoricschilean NMO

Problem Statement

p1. A conical bottle perched on its base is filled with water up to a height that is 8 8 cm of its vertex. When the bottle is turned over the water level is at 22 cm from its base. Calculate the height of the bottle.
p2. A square with side 8 8 cm is divided into 6464 squares of 1 1 cm2^2. 77 little squares are colored black and the rest white. Find the maximum area of a rectangle composed only of small white squares independent of the distribution of the little black squares.
p3. From a 10001000-page book, a quantity has been ripped of consecutive of leaves. It is known that the sum of the numbers of the torn pages is 20182018. Determine the numbering of the ripped pages.
p4. Given a rhombus ABCDABCD, a circle with center at the midpoint of side ABAB and with diameter ABAB is drawn, which intersects side BCBC at the point KK. Similarly, a circle is drawn with its center at the midpoint of side ADAD and of diameter ADAD that cuts to the side CDCD at point LL. Suppose that AKL=ABC\angle AKL = \angle ABC. Determine the angles of the rhombus sides are equal.
PS. Juniors p2, p3 were posted as [url=https://artofproblemsolving.com/community/c4h2691340p23361294]Seniors p2,p1 respectively.