conversations.from: human
conversations.value: In a 90-minute soccer game, Mark played 20 minutes, then rested after. He then played for another 35 minutes. How long was he on the sideline?
  Give me a solution to this problem
conversations.from: assistant
conversations.value: Mark played for a total of 20 + 35 = 55 minutes.
  So, he was on the sideline for 90 - 55 = 35 minutes.