The number of girls/boys someone says multiply/divide it by 3. If its a guy, take the number of girls they said and divide it by 3, if it's a girl take the number of guys and multiply if my 3.
" I slept with 3 girls over break."
"Did you hear that guy, three girls!"
" nah dude, you don't know the Rule 3?"
" Oh yeah, Divide it by 3. He only slept with one girl."