conversations.from: human
conversations.value: Ellen is baking bread. It takes 3 hours to rise 1 ball of dough, and then another 2 hours to bake it. If she makes 4 balls of dough one after another and then bakes them one after another when they're done rising, how many hours will it take?
conversations.from: assistant
conversations.value: Ellen takes 4*3=12 hours in total to rise all balls of dough.
  It will take 4*2=8 more hours to bake each one.
  It will take her 12+8=20 hours to make all of the bread.