Teacher: How many kids are in this classroom?
Kid: 73 if you count the ones you have hid in the basement.
Teacher: How many kids are in this classroom?
Kid: 73 if you count the ones you have hid in the basement.
Okay, so basically, the teacher asks how many kids are in the classroom, right? But the kid implies that the teacher has kids hidden in the basement! It's funny because it's dark and unexpected. Also, you are probably not a teacher, so the chance of you hiding kids in the basement is low.