###Human: Janet has a business selling custom collars for dogs and cats. If it takes 18 inches of nylon to make a dog collar and 10 inches to make a cat collar, how much nylon does she need to make 9 dog collars and 3 cat collars?, ### Assistant: First find the total number of inches of nylon used for the dog collars: 18 inches/dog collar * 9 dog collars = 162 inches
Then find the total number of inches of nylon used for the cat collars: 10 inches/cat collar * 3 cat collars = 30 inches
Then add the nylon needed for the cat and dog collars to find the total amount needed: 162 inches + 30 inches = 192 inches 
 So the answer is :  192