conversations.from: human
conversations.value: In a factory, there are 3 machines working 23 hours a day. The owner decided to buy a fourth machine, which works only 12 hours a day. One machine can produce 2 kg of material every hour. The factory sells the produced material for $50 per 1 kg. How much can this factory earn in one day?
  Give me a solution to this problem
conversations.from: assistant
conversations.value: The total runtime for the first three machines is 3 machines * 23 hours/day/machine = 69 hours/day.
  So these machines could produce 69 hours/day * 2 kg/hour = 138 kg/day.
  The fourth machine could produce 12 hours/day * 2 kg/hour = 24 kg/day of material.
  In total all the machines would produce 138 kg/day + 24 kg/day = 162 kg/day of material.
  The factory would therefore earn 162 kg/day * $50/kg = $8100/day.