A department organized a blind date activity, and ***6 people signed up, including 3 boys. After being divided into two groups according to gender, they enter the mutual selection link, and each round of mutual selection needs to select another group.
Everyone has three choices, and six people always have 3 6 choices.
Calculate all successful mutual selection by multiplication principle.
The first person has three choices, the second one has two, and the last one has only 1, so only six matches are successful.
The answer is 6/3 6 = 2/3 5.