Ms. Wong's class had 11 girls and 14 boys. What is the probability that a girl will get the infection first and then a boy ?

25,67%

Step-by-step explanation:

We have 11 girls and 14 boys, this is a total of 11 + 14 = 25 students.

If all the students have the same probability of being infected, the probability that a girl will get infected first is equal to the number of girls dividedthe total number of students:

p1 = 11/25

Now we get a boy infected, the number of boys is 14, and the total number of students is now 24 (because we already have a girl infected)

this probability is p2 = 14/24

The probability for both events is equal to the product of the probabilities:

P = p1*p2 = (11/25)*(14/24) = 0.2567

or 25,67%