conversations.from: human
conversations.value: There are 4 trains waiting at a train station and each train has 4 carriages. Each carriage has 3 rows of wheels and the rows of wheels have 5 wheels each. How many wheels are at the train station?
conversations.from: assistant
conversations.value: Each carriage has 3 rows of wheels * 5 wheels per row = 15 wheels.
  So each train has 4 carriages * 15 wheels per carriage = 60 wheels.
  There is therefore a total of 4 trains * 60 wheels per train = 240 wheels at the train station.