conversations.from: human
conversations.value: Solve the following math problem: A school has 1000 students. Half of the students were taken on a trip to the nearby beach. Half of the remaining students were sent home. How many students are still in the school?
conversations.from: assistant
conversations.value: 1000 * 1/2 = 500 students were taken on a trip to the nearby beach.
  So 1000 - 500 = 500 students were not taken to the beach.
  Thus, 1/2 * 500 = 250 students who were not taken to the beach were sent home.
  Thus, 500 - 250 = 250 students are still in school.