MathDB

10

Part of PEN F Problems

Problems(1)

F 10

Source:

5/25/2007
The set S S is a finite subset of [0,1] [0,1] with the following property: for all s∈S s\in S, there exist a,b∈S∪{0,1} a,b\in S\cup\{0,1\} with a,b≠s a, b\neq s such that s \equal{}\frac{a\plus{}b}{2}. Prove that all the numbers in S S are rational.
irrational numberrational numbers