By coincidence, Trevor's Obedience School trained the same number of dogs and cats last week. The school teaches dogs in groups of 7 and cats in groups of 15. What is the smallest number of cats the school could have had?
Question
By coincidence, Trevor's Obedience School trained the same number of dogs and cats last week. The school teaches dogs in groups of 7 and cats in groups of 15. What is the smallest number of cats the school could have had?
Solution
To find the smallest number of cats the school could have had, we need to find the least common multiple (LCM) of 7 and 15. The LCM is the smallest number that is a multiple of both numbers.
Here are the steps to find the LCM:
-
List the prime factors of each number:
- The prime factors of 7 are 7.
- The prime factors of 15 are 3 and 5.
-
Multiply each factor the greatest number of times it occurs in either number:
- 7 occurs once in the factors of 7 and does not occur in the factors of 15. So, we multiply by 7 once.
- 3 occurs once in the factors of 15 and does not occur in the factors of 7. So, we multiply by 3 once.
- 5 occurs once in the factors of 15 and does not occur in the factors of 7. So, we multiply by 5 once.
-
Multiply the results from step 2 together:
- 7 * 3 * 5 = 105
So, the smallest number of cats the school could have had is 105.
Similar Questions
Jamie and Nathan make money by walking neighborhood pets. During a conversation about their work, they realize that they are both walking the same total number of pets, even though Jamie walks pets in groups of 3 and Nathan walks pets in groups of 4. What is the smallest total number of pets each could be walking?
Bobby tutors students in groups of 8. Meanwhile, Polly tutors students in groups of 12. While discussing their work, the tutors realize that they both work with the same total number of students. What is the smallest number of students each can have?
Florence tutors students in groups of 18. Meanwhile, Harold tutors students in groups of 13. While discussing their work, the tutors realize that they both work with the same total number of students. What is the smallest number of students each can have?
The ratio of cats to dogs is 5 to 16. If there are 84 total cats and dogs,how many cats are there?
In a class of 18 students, 7 have a cat and 12 have a dog. There are 2 students who do not have a cat or a dog. What is the probability that a student who has a cat also has a dog?
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.