A boy walks down the sidewalk with a trash bag while two other boys follow him .
It is highly unlikely that a boy picks up litter while his classmates make fun of him .
It is highly unlikely that a boy picks up litter while his classmates make fun of him .
There is a better than even chance that a boy picks up litter while his classmates make fun of him .
A boy picks up litter while his classmates make fun of him .