A class has three girls and three boys.

A class has three girls and three boys. These students line up at random, one after another. What is the probability that no boy is right next to another boy, and no girl is right next to another girl?

Quiz

Answer/Solution

1 /10

Steps/Work

We pick the students in order. The first choice is always okay. There is a probability
3/5 that the second choice is okay; for example, if you picked a boy first then there are two boys
and three girls left. Similarly the probabilities that the remaining choices are okay is 1/2 , 2/3 , 1/2,1. The answer is 1/10 , the product of all these probabilities.
correct answer C