Let Qn be the graph obtained from the n-dimensional unit cube 0, 1)", whose vertices and edges are the vertices and edges of the n-cube [0, 1]". The graph Qn can be also defined as follows: V(Qn) is the set of zero-one sequences of length n, and two such sequences are adjacent if and only if they differ at only one position. (1) For which n the graph Q, has an Euler tour or an Euler path? (2) For what n the graph Qn is non-planar? Why? (3) For what n the graph Qn has a Hamilton cycle or Hamilton path? (4) Is Qn bipartite