Samantha has a total of 12 chickens. If she has 3 times as many chickens as dogs, write and solve an equation to determine the number of dogs she has.
Let's assume Samantha has x dogs.
Since Samantha has 3 times as many chickens as dogs, she has 3*x chickens.
The total number of chickens and dogs is x + 3*x = 4*x.
We know that 4*x = 12.
Dividing both sides of the equation by 4 gives x = 12/4 = <<12/4=3>>3.
Samantha has 3 dogs. Answer: \boxed{3}.