There are 15 males and 10 girls in each class. At random, three pupils are chosen. The likelihood of one girl and two boys being chosen is:
A. 21/46
B. 25/117
C. 1/50
D. 3/25
Answer:A
There are 15 males and 10 girls in each class. At random, three pupils are chosen. The likelihood of one girl and two boys being chosen is:
A. 21/46 B. 25/117 C. 1/50 D. 3/25
Explanation: Let S represent the sample space, and E represent the event of picking one female and two males.Then, n(S) = Number of methods to choose three students from a group of 25 = 25C3 = (25 x 24 x 23)/ (3 x 2 x 1),n(E) = (10C1 x 15C2) = 10 x (15 x 14) / 2300 (2 x 1).P(E) = n(E)/n(S) = 1050/2300 = 21/46