Question

a science class has 8 juniors and 4 seniors. the teacher will randomly select 2 students, one at a time, to represent the class in a committee at the school. given that the first student selected is a junior, what is the probability that the second student selected will be a senior?
a $\frac{1}{11}$
b $\frac{1}{4}$
c $\frac{1}{3}$
d $\frac{4}{11}$

Explanation:

Step1: Update total student count

After selecting 1 junior, total remaining students: $8 + 4 - 1 = 11$

Step2: Identify remaining seniors

Number of seniors remains unchanged: $4$

Step3: Calculate conditional probability

Probability = $\frac{\text{Remaining seniors}}{\text{Remaining total students}} = \frac{4}{11}$

Answer:

D. $\frac{4}{11}$