Question

20 people are seated around a circular table. In how many ways can they all simultaneously be shaking hands with others in the table, so that none of the arms cross each other. 20people are seated a round a circular table. In how many ways can they all simultaneously be shaking hands with others in the table,so that none of the arms cross each other.20 people are seated around a circular table.In how many ways cant hey all simultaneously be shaking hands with others in the table,so that none of the arms cross each other. 20 people are seated around a circular table.In how many ways can they all simultaneously be shaking hands with others in the table,so that none of the arms cross each other.

Answer 1