(17) Prove that the ring Zm Xx Z, is not isomorphic to Zmn if m and n are not relatively prime.
Permutations and Combinations
If there are 5 dishes, they can be relished in any order at a time. In permutation, it should be in a particular order. In combination, the order does not matter. Take 3 letters a, b, and c. The possible ways of pairing any two letters are ab, bc, ac, ba, cb and ca. It is in a particular order. So, this can be called the permutation of a, b, and c. But if the order does not matter then ab is the same as ba. Similarly, bc is the same as cb and ac is the same as ca. Here the list has ab, bc, and ac alone. This can be called the combination of a, b, and c.
Counting Theory
The fundamental counting principle is a rule that is used to count the total number of possible outcomes in a given situation.
Please answer the question in the image shown below:
![**Problem 17:**
Prove that the ring \( \mathbb{Z}_m \times \mathbb{Z}_n \) is not isomorphic to \( \mathbb{Z}_{mn} \) if \( m \) and \( n \) are not relatively prime.
**Explanation:**
In this problem, you are asked to demonstrate that the direct product of the rings \( \mathbb{Z}_m \) and \( \mathbb{Z}_n \) cannot be isomorphic to the ring \( \mathbb{Z}_{mn} \) under the condition that the integers \( m \) and \( n \) have a common divisor greater than 1. The proof requirements hinge on properties of ring isomorphisms and the significance of relatively prime numbers in modular arithmetic. Ring isomorphisms are structure-preserving bijections between two algebraic structures, implying the two structures have identical algebraic properties. Differences in properties like size and unit elements will play key roles in showing the absence of an isomorphism in this scenario.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2Fe5ef7b9b-7f40-491c-b8c0-9669ee1e8bbc%2F90b75734-c951-4bf6-b279-946a3f5544e7%2Fq94ty8_processed.jpeg&w=3840&q=75)
![](/static/compass_v2/shared-icons/check-mark.png)
Trending now
This is a popular solution!
Step by step
Solved in 3 steps with 2 images
![Blurred answer](/static/compass_v2/solution-images/blurred-answer.jpg)
![Advanced Engineering Mathematics](https://www.bartleby.com/isbn_cover_images/9780470458365/9780470458365_smallCoverImage.gif)
![Numerical Methods for Engineers](https://www.bartleby.com/isbn_cover_images/9780073397924/9780073397924_smallCoverImage.gif)
![Introductory Mathematics for Engineering Applicat…](https://www.bartleby.com/isbn_cover_images/9781118141809/9781118141809_smallCoverImage.gif)
![Advanced Engineering Mathematics](https://www.bartleby.com/isbn_cover_images/9780470458365/9780470458365_smallCoverImage.gif)
![Numerical Methods for Engineers](https://www.bartleby.com/isbn_cover_images/9780073397924/9780073397924_smallCoverImage.gif)
![Introductory Mathematics for Engineering Applicat…](https://www.bartleby.com/isbn_cover_images/9781118141809/9781118141809_smallCoverImage.gif)
![Mathematics For Machine Technology](https://www.bartleby.com/isbn_cover_images/9781337798310/9781337798310_smallCoverImage.jpg)
![Basic Technical Mathematics](https://www.bartleby.com/isbn_cover_images/9780134437705/9780134437705_smallCoverImage.gif)
![Topology](https://www.bartleby.com/isbn_cover_images/9780134689517/9780134689517_smallCoverImage.gif)