Harry is a professional dog-walker.  He is paid to go on long walks with dogs while their families are away from home.  On Monday, Wednesday, and Friday, Harry walks 7 dogs.  On Tuesday, he walks 12 dogs.  And on Thursday he walks 9 dogs.  He is paid $5 for each dog that he walks.  How many dollars does Harry earn in a week?
Monday, Wednesday, and Friday, Harry walks a total of 3 * 7 = <<3*7=21>>21 dogs.
Thus, in a week he walks 21 + 12 + 9 = <<21+12+9=42>>42 dogs.
At a rate of $5 per dog, Harry ears $5 * 42 = $<<5*42=210>>210 per week.
#### 210