MathDB

4

Part of 2015 Junior Balkan Team Selection Tests - Moldova

Problems(1)

game with numbers 1, 2,. . . , 33 are written on the board

Source: 2015 Moldova JBMO TST p4

2/25/2021
The numbers 1,2,...,331, 2,. . . , 33 are written on the board . A student performs the following procedure: choose two numbers from those written on the board so that one of them is a multiple of the other number; after the election he deletes the two numbers and writes on the board their number. The student repeats the procedure so many times until only numbers without multiples remain on the board. Determine how many numbers they remain on the board in the situation where the student can no longer repeat the procedure.
combinatoricsgame