The Hungry Tiger Trolley
You are standing next to a trolley track, and a hungry tiger is running toward the trolley standing at the station, heading towards a group of unsuspecting passengers.
Pulling the lever will cause the trolley to drive away, but that track is also next to the home to a herd of wild bulls. If you don't pull the lever, the tiger will tear apart the passengers.
If you pull the lever:
The bulls will stampede in panic, charging towards a nearby village. The villagers will scramble in terror, but the bulls will trample only a few of them, sparing most of the lives. The tiger, meanwhile, will pout at the loss of its lunch.
If you don't pull the lever:
The tiger will feast on the hapless passengers, but the trolley will safely stay at the station. The remaining passengers will arrive late and complain about the smell of tiger breath.