Question

There are seven boys and five girls in a class. The teacher randomly selects three different students to answer questions. The first student is a girl, the second student is a boy, and the third student is a girl. Find the probability of this occuring.A. 7/66B. 1/32C. 25/429D. 100/2197

Answer 1

number of boys = 7

number of girls = 5

Total students = 7 + 5 = 12

Therefore, the probability of selecting a girl, a boy, and a girl can be computed below

$\frac{5}{12}\times\frac{7}{11}\times\frac{4}{10}=\frac{140}{1320}=\frac{14}{132}=\frac{7}{66}$

Recall probability can be expressed mathematically as follows

$p(x)=\frac{\text{ number of favorable outcome to x}}{\text{Total number of outcome}}$