###Human: For every 1 year a human ages, a dog ages 7 years.  When Max is 3, how much older, in dog years, will his 3-year-old dog be?, ### Assistant: The 3-year-old dog ages 7 years to one human year so he will technically be 3*7 = 21 years old in dog years
Max's dog will be 21 when Max turns 3 so the age difference is 21-3 = 18 
 So the answer is :  18