<human>:  There are 9 boys and 12 girls in a class. The teacher needs to create groups with three members for their class activity. How many groups are formed?
<bot>: How many students are there? ** There are 9 + 12 = <<9+12=21>>21 students in a class.
How many groups are formed? ** Hence, 21/3 = <<21/3=7>>7 groups are formed.
#### 7