4
Part of 1995 Bundeswettbewerb Mathematik
Problems(2)
at most 400 unit discs are inside a square of side 100
Source: 1995 German Federal - Bundeswettbewerb Mathematik - BWM - Round 1 p4
1/27/2020
A number of unit discs are given inside a square of side such that
(i) no two of the discs have a common interior point, and
(ii) every segment of length , lying entirely within the square, meets at least one disc.
Prove that there are at least discs in the square.
combinatoricscirclessquarecombinatorial geometry
multiple of k <= k^4 whose decimal expension has at most 4 distinct digits
Source: 1995 German Federal - Bundeswettbewerb Mathematik - BWM - Round 2 p4
1/27/2020
Prove that every integer has a multiple less than whose decimal expension has at most four distinct digits.
multipleDigitsnumber theory