Question

In a class 22 of students, 14 have a brother and 9 have a sister. There are 2 students who do not have any siblings. What is the probability that a student chosen randomly from the class has a sibling?

Answer 1

I believe this is the way to solve it.
 22 - 2 = 20
 20 is 90.9% of 22
So the probability of choosing a student with a sibling at random should be 90.9% (or you can round up to 91%)

I hope this helps :)