A group of five people consists of two women, Alice and Betty, and three men, Carl, David and Ed.

(i) Three of these five people are chosen at random to be a chairperson, a treasurer and a secretary. Find the number of ways in which this can be done if the chairperson and treasurer are both men.

These five people sit in a row of five chairs. Find the number of different possible seating arrangements if

(ii) David must sit in the middle,

(iii) Alice and Carl must sit together.