Eden's mom is twice as old as Eden, who is twice as old as Devin. If Devin is 12 years old, what's the average age of the three?
If Devin is 12 years old, then Eden is 2 * 12 years = 24 years old.
Since Eden's mom two times older than Eden, her age is 24 years * 2 = <<24*2=48>>48 years.
In total, they have 48 years + 24 years + 12 years = <<48+24+12=84>>84 years
The average age for the three is 84 years / 3 people = <<84/3=28>>28 years/person
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