4 couples are there. 2 persons are selected from 8 persons.
(i) Two persons selected are husband and wife:
If selected two persons are husband and wife. then they are one couple of 4 couples.
∴ Total combinations = 4C1 = 4
(iii) One Is a male and the other is a female:
In 8 persons, 4 are males and 4 are females.
One male can be selected in 4C1 ways andone female can be selected In 4C1 ways.
∴ Total combinatíons = 4C1 × 4C1 = 4 × 4 = 16
(iii) One is a male and the other is a female but they are not husband and wife:
Total combinations
[Total combinations in which one is a male and one is female – Total combinations in which they are husband and wife]
= 16 – 4 = 12