1 vote

A system where commutativity is considered different, in how many ways the join of n relations r1,r2,…, rn can be taken?

1. (2n−2)!/(n−1)!

2. (2n−2)!/n!(n−1)!

3. (2n−1)!/n!(n−1)!

4. None

1. (2n−2)!/(n−1)!

2. (2n−2)!/n!(n−1)!

3. (2n−1)!/n!(n−1)!

4. None