human
John is twice as old as Mary and half as old as Tonya. If Tanya is 60, what is their average age?
assistant
How old is John? ** John is 30 because 60 / 2 = <<60/2=30>>30
How old is Mary? ** Mary is fifteen because 30 / 2 = <<30/2=15>>15
How old are they? ** Their total age is 105 because 60 + 30 + 15 = <<60+30+15=105>>105
What is their average age? ** Their average age is 35 because 105 / 3 = <<105/3=35>>35
#### 35