conversations.from: human
conversations.value: Provide a step by step solution for the following math problem: Mary is two years younger than Joan, who is five years older than Jessa. If Jessa is 20 years old, what is the sum of the ages of the three girls?
conversations.from: assistant
conversations.value: Joan is 20 + 5 = 25 years old.
  Mary is 25 – 2 = 23 years old.
  Therefore, the sum of their ages is 20 + 25 + 23 = 68.