The pet shop grooms dogs. It takes 30 minutes to groom a poodle. It takes half as much time to groom a terrier as it takes to groom a poodle. They do not groom cats. If the pet shop grooms 3 poodles and 8 terriers, what is the total length of time it will take, in minutes? Let's answer step by step:
At a rate of 30 minutes per poodle, 3 poodles will take 3 * 30 = 90 minutes. If it takes half as much time to groom a terrier as it takes to groom a poodle, it takes 30 / 2 = 15 minutes per terrier. At a rate of 15 minutes per terrier, 8 terriers will take 120 minutes. Thus, in total, it will take the pet shop 90 + 120 = 210 minutes to groom 3 poodles and 8 terriers. The answer: 210.