MathDB
TOT 328 1992 Spring A J5 7 weighings for 101 coins

Source:

June 9, 2024
combinatoricsweighings

Problem Statement

5050 silver coins ordered by weight and 5151 gold coins also ordered by weight are given. All coins have different weights. You are given a balance to compare weights of any two coins. How can you find the “middle” coin (that occupying the 5151st place in weight among all 101101 coins) using 77 weighings?
(A. Andjans)