conversations.from: human
conversations.value: Romeo boards a train with 120 people. At the first stop, 20 more people board the train. At the second stop, 50 people descended from the train while twice that number boarded the train. If 80 more people descended at the third station, calculate the total number of people on the train at the final stop.
conversations.from: assistant
conversations.value: After the first stop, 120+20 = 140 were on the train.
  At the second stop, 140 - 50 = 90 people remain when 50 descended.
  However, 50*2 = 100 more people boarded the train.
  After the second stop, the total number of people was 90+100 =190
  At the third stop, the number of people on the train decreased to 190-80 = 110 who reached the final stop.