conversations.from: human
conversations.value: James buys pistachios for $10 per can.  Each can is 5 ounces.  He eats 30 ounces of pistachios every 5 days.  How much does he spend on pistachios per week?
  How to solve this?
conversations.from: assistant
conversations.value: The pistachios cost 10/5=$2 per ounce
  He eats 30/5=6 ounces of pistachios a day
  So he spends 6*2=$12 per day on pistachios
  So he spends 12*7=$84 per week