A hint to get started
Use the same equally likely four-person selections throughout
Four persons are chosen at random from ten persons consisting of four men and six women. Three of the women are sisters. Calculate the probability that the four persons chosen will
(i) consist of four women,
(ii) consist of two women and two men,
(iii) include the three sisters.
CJC · Discussion · Question 3
Count unordered groups in both numerator and denominator.