Scanning for The Coin
Source: Iranian Combinatorics Olympiad 2020 P7
April 26, 2020
combinatoricscoins
Problem Statement
Seyed has 998 white coins, a red coin, and an unusual coin with one red side and one white side. He can not see the color of the coins instead he has a scanner which checks if all of the coin sides touching the scanner glass are white. Is there any algorithm to find the red coin by using the scanner at most 17 times?Proposed by Seyed Reza Hosseini