Question

In a class of 28 students, 21 have a brother and 9 have a sister. There are 7 students

Answer 1

Answer:

Step-by-step explanation:

28 students in total

21 - 7 = 14 students only has a brother

9 - 7 = 2 students only have a sister

7 students have both brothers and sisters

probability of a student having a brother and a sister:

$\frac{7}{28} = \frac{1}{4}$

Answer 2

1/4

because not a lot of students have both gender as siblings!