1
Part of 2007 Hungary-Israel Binational
Problems(2)
Designing a Procedure to Randomly Select People
Source: Hungary-Israel Mathematical Competition 2007 Problem 1
11/19/2007
You have to organize a fair procedure to randomly select someone from people so that every one of them would be chosen with the probability . You are allowed to choose two real numbers and and order two coins which satisfy the following requirement: the probability of tossing "heads" on the first coin and the probability of tossing "heads" on the second coin is . Before starting the procedure, you are supposed to announce an upper bound on the total number of times that the two coins are going to be flipped altogether. Describe a procedure that achieves this goal under the given conditions.
probabilityinequalitiesfunctioncombinatorics unsolvedcombinatorics
Finding Area of a Rectangle Based on Areas of Smaller Ones
Source: Hungary-Israel Mathematical Competition 2007 Problem 4
11/19/2007
A given rectangle is divided into small rectangles by straight lines parallel to its sides. (The distances between the parallel lines may not be equal.) What is the minimum number of appropriately selected rectangles’ areas that should be known in order to determine the area of ?
geometryrectangleinductioncombinatorics unsolvedcombinatorics