conversations.from: human
conversations.value: Emily is 20 years old and her older sister, Rachel, is 24 years old.  How old is Rachel when Emily is half her age?
  Give me a solution to this problem
conversations.from: assistant
conversations.value: The difference in age between the two sisters is 24 - 20 = 4 years.
  When Rachel is twice Emily’s age, she is 4 x 2 = 8 years old.