premise: Few people hitch a ride on the back of a garbage truck. hypothesis: Few people are riding  irrately on the back of a garbage truck.
entailment: Since a garbage truck implies there is garbage on it, with the garbage exposed at the back, and since garbage is unpleasant, it would be expected that few people would be riding on it as most people stay away from unpleasant things. Riding irately implies the people are reacting negatively to the unpleasantness.