Answer 4: Bring the goat BACK 🐐
The wolf and cabbage don’t interact, so take the goat across first. Return alone. Take the wolf across. Drop the wolf, but bring the goat BACK with you. Drop the goat, take the cabbage across. Return alone. Finally take the goat across. Seven crossings total. The trick is the counterintuitive “bring the goat back” step.
