TOT 136 1987 Spring Main J1 machine gives 5 pennies for each nickel
Source:
April 17, 2020
combinatorics
Problem Statement
A machine gives out five pennies for each nickel inserted into it and five nickels for each penny. Can Peter , who starts out with one penny, use the machine several times in such a way as to end up with an equal number of nickels and pennies?(F. Nazarov, Leningrad Olympiad, 1987)