7. From among a group of 4 men and 6 women, 3 persons are to be appointed as a braneina in three different cities. How many different appointments can be made under the following circumstances? (order of the cities matters) (a) Any person is eligible for appointment (b) One man and two women are to be appointed. (c) At least two men are to be appointed. (d) At least one person of each gender is to be appointed