Graph theory questions

Q1) Is graph of 21 vertices and each vertex has degree 11 exist ? explains with reason

(No need to draw graph)

Q2 ) Draw following graphs and check whether it is bipartite or not

a) k₉

b) Q₄ (4-cube graph)

c) K_{6 ,5}

Q3) Is graph Q₄ eulerian graph ? if yes then give euler cycle