MathDB

(256) 4

Part of 1990 Tournament Of Towns

Problems(1)

TOT 256 1990 Spring O S4 103 coins

Source:

6/8/2024
A set of 103103 coins that look alike is given. Two coins (whose weights are equal) are counterfeit. The other 101101 (genuine) coins also have the same weight, but a different weight from that of the counterfeit coins. However it is not known whether it is the genuine coins or the counterfeit coins which are heavier. How can this question be resolved by three weighings on the one balance? (It is not required to separate the counterfeit coins from the genuine ones.)
(D. Fomin, Leningrad)
combinatorics