If in six years Tom's brother will be 30 years old, he is currently 30-6 = <<30-6=24>>24 years old.

Since Tom's brother is 4 times as old as Tom's dog, Tom's dog is 24/4 = <<24/4=6>>6 years old currently.

Tom's dog will be 6+6 = <<6+6=12>>12 years old in six years.

# Answer

12
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Tom's brother is 4 times as old as Tom's dog. If in 6 years, Tom's brother will be 30 years, how old is Tom's dog going to be in six years?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
12
Tom's brother is 4 times as old as Tom's dog. If in 6 years, Tom's brother will be 30 years, how old is Tom's dog going to be in six years?
train