Find Two Natural Numbers Whose Difference Is 66 And The Least Common Multiple Is 360.

by ADMIN 86 views

Introduction: The Intriguing World of Number Theory

In the captivating realm of number theory, we often encounter puzzles that challenge our understanding of the fundamental properties of numbers. One such puzzle involves finding two natural numbers that satisfy specific conditions. In this case, we are tasked with identifying two numbers whose difference is 66 and whose least common multiple (LCM) is 360. This problem, while seemingly simple, requires a blend of algebraic manipulation, prime factorization, and a dash of logical reasoning. Let's embark on this mathematical journey and unravel the mystery behind these elusive numbers.

To begin, let's define our variables. Let the two natural numbers be represented by 'x' and 'y', where x > y. We are given two crucial pieces of information: their difference is 66, and their least common multiple (LCM) is 360. Translating these into mathematical equations, we have:

  1. x - y = 66
  2. LCM(x, y) = 360

Our goal is to find the values of x and y that simultaneously satisfy both of these equations. To tackle this, we'll need to delve into the properties of LCM and explore how it relates to the numbers themselves.

Deciphering the Least Common Multiple (LCM)

The least common multiple (LCM) of two numbers is the smallest positive integer that is divisible by both numbers. To understand LCM better, we often turn to prime factorization. Every natural number greater than 1 can be expressed as a unique product of prime numbers. The prime factorization of a number reveals its fundamental building blocks.

Let's find the prime factorization of 360, our given LCM. Through successive division by prime numbers, we find:

360 = 2^3 * 3^2 * 5

This prime factorization tells us that any number that divides 360 can only have the prime factors 2, 3, and 5, raised to powers no greater than their respective powers in the factorization of 360. In other words, if a number divides 360, it must be of the form 2^a * 3^b * 5^c, where 0 ≤ a ≤ 3, 0 ≤ b ≤ 2, and 0 ≤ c ≤ 1.

Now, consider our two numbers, x and y. Since their LCM is 360, both x and y must be factors of 360. This is a crucial piece of the puzzle. We can express x and y in terms of their prime factorizations as follows:

x = 2^a1 * 3^b1 * 5^c1 y = 2^a2 * 3^b2 * 5^c2

where 0 ≤ a1, a2 ≤ 3, 0 ≤ b1, b2 ≤ 2, and 0 ≤ c1, c2 ≤ 1. The LCM of x and y is then given by taking the highest power of each prime factor present in either x or y:

LCM(x, y) = 2^max(a1, a2) * 3^max(b1, b2) * 5^max(c1, c2) = 2^3 * 3^2 * 5

This tells us that max(a1, a2) = 3, max(b1, b2) = 2, and max(c1, c2) = 1. This means that at least one of x or y must have 2 raised to the power of 3, at least one must have 3 raised to the power of 2, and at least one must have 5 raised to the power of 1.

Leveraging the Difference: x - y = 66

We've extracted valuable information from the LCM condition. Now, let's bring in the second piece of the puzzle: x - y = 66. This equation establishes a direct relationship between x and y, allowing us to further narrow down the possibilities.

We can rewrite the equation as:

x = y + 66

This tells us that x is simply y plus 66. Now, we need to find a value for y such that y and y + 66 are both factors of 360 and their LCM is indeed 360. This is where a systematic approach becomes essential.

Let's consider the factors of 360. They are:

1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 30, 36, 40, 45, 60, 72, 90, 120, 180, 360

We need to find a pair of factors (y, x) such that their difference is 66. Let's systematically check the factors, starting from the smaller ones.

If y = 1, then x = 67, which is not a factor of 360. If y = 2, then x = 68, which is not a factor of 360. If y = 3, then x = 69, which is not a factor of 360. …

This process can be tedious, but it's a methodical way to explore the possibilities. Alternatively, we can use the information we gleaned from the prime factorization of the LCM to guide our search.

Combining Insights: A Strategic Approach

Let's revisit the prime factorization of 360 (2^3 * 3^2 * 5) and the equation x = y + 66. We know that both x and y must be factors of 360. Also, we know that at least one of x or y must have 2^3 as a factor, at least one must have 3^2 as a factor, and at least one must have 5 as a factor. This knowledge will help us in searching the number.

Let's analyze the numbers.

We have x= 90 and y= 24

By doing the math, we know that 90-24 = 66, this matches the number difference mentioned in the question. And the LCM(90,24) = 360, this also matches the requirement.

The Solution Unveiled

Through a combination of prime factorization, LCM properties, and systematic checking, we arrive at the solution. The two natural numbers whose difference is 66 and whose least common multiple is 360 are 24 and 90.

In summary:

  • The two numbers are 24 and 90.
  • Their difference is 90 - 24 = 66.
  • Their LCM is LCM(24, 90) = 360.

This problem exemplifies the beauty and power of number theory. It showcases how seemingly simple conditions can lead to intriguing challenges that require a blend of mathematical tools and logical reasoning. The solution not only provides the answer but also deepens our understanding of the relationships between numbers and their fundamental properties.

This exploration of two natural numbers with a specific difference and LCM highlights the elegance and interconnectedness of mathematical concepts. By understanding the properties of LCM and prime factorization, we can unravel seemingly complex problems and appreciate the beauty of numbers.

Understanding the Problem

In the realm of mathematics, particularly in the field of number theory, we often encounter intriguing problems that require us to find numbers satisfying certain conditions. One such problem involves identifying two natural numbers where the difference between them is 66, and their least common multiple (LCM) is 360. This problem is a classic example of how basic mathematical concepts can be combined to create challenging and rewarding puzzles. Let's delve into the problem and explore the steps involved in finding the solution.

Before we proceed, let's clarify some key terms. Natural numbers are positive integers (1, 2, 3, ...). The difference between two numbers is the result of subtracting the smaller number from the larger number. The least common multiple (LCM) of two numbers is the smallest positive integer that is divisible by both numbers. With these definitions in mind, we can rephrase the problem statement: We are looking for two positive whole numbers that, when subtracted, yield 66, and the smallest number divisible by both of them is 360.

To approach this problem effectively, we need to translate the given information into mathematical equations. Let's represent the two natural numbers as 'x' and 'y', where x > y. The problem provides us with two crucial pieces of information:

  1. The difference between the numbers is 66: x - y = 66
  2. The least common multiple of the numbers is 360: LCM(x, y) = 360

Our task is to find the values of x and y that satisfy both of these equations simultaneously. This requires us to utilize our knowledge of LCM, factors, and potentially some algebraic manipulation.

Deconstructing the LCM: Prime Factorization

The least common multiple (LCM) is a fundamental concept in number theory. It represents the smallest number that is a multiple of two or more given numbers. To effectively work with LCM, we often employ the technique of prime factorization. Prime factorization is the process of breaking down a number into its prime factors, which are prime numbers that multiply together to give the original number. Every integer greater than 1 can be uniquely represented as a product of prime numbers.

Let's find the prime factorization of 360, our given LCM. We can do this by repeatedly dividing 360 by the smallest prime number that divides it evenly, and then repeating the process with the quotient until we are left with 1. The prime factors we find along the way are the prime factors of 360.

360 ÷ 2 = 180 180 ÷ 2 = 90 90 ÷ 2 = 45 45 ÷ 3 = 15 15 ÷ 3 = 5 5 ÷ 5 = 1

Therefore, the prime factorization of 360 is 2 * 2 * 2 * 3 * 3 * 5, which can be written more compactly as 2^3 * 3^2 * 5. This prime factorization is crucial because it provides us with the building blocks of all the factors of 360. Any number that divides 360 must have a prime factorization that is a subset of the prime factors of 360. This means that any factor of 360 can only have the prime factors 2, 3, and 5, raised to powers no greater than their respective powers in the prime factorization of 360.

Now, let's consider our two numbers, x and y. Since their LCM is 360, both x and y must be factors of 360. This is a key insight that will help us narrow down the possible values of x and y. We can express x and y in terms of their prime factorizations as follows:

x = 2^a1 * 3^b1 * 5^c1 y = 2^a2 * 3^b2 * 5^c2

where a1, a2 are integers between 0 and 3 (inclusive), b1, b2 are integers between 0 and 2 (inclusive), and c1, c2 are integers between 0 and 1 (inclusive). The LCM of x and y is then given by taking the highest power of each prime factor present in either x or y:

LCM(x, y) = 2^max(a1, a2) * 3^max(b1, b2) * 5^max(c1, c2) = 2^3 * 3^2 * 5

This equation tells us that max(a1, a2) = 3, max(b1, b2) = 2, and max(c1, c2) = 1. In other words, at least one of x or y must have 2 raised to the power of 3, at least one must have 3 raised to the power of 2, and at least one must have 5 raised to the power of 1. This information significantly reduces the number of possibilities we need to consider.

Utilizing the Difference: x - y = 66

We've extracted significant insights from the LCM condition and the prime factorization of 360. Now, let's incorporate the second crucial piece of information: x - y = 66. This equation establishes a direct relationship between x and y, allowing us to further constrain the possible solutions.

We can rearrange the equation as:

x = y + 66

This equation tells us that x is equal to y plus 66. Now, we need to find a value for y such that both y and y + 66 are factors of 360, and their LCM is indeed 360. This requires a systematic approach, combining our knowledge of factors, LCM, and the difference equation.

Let's list the factors of 360 to provide a concrete foundation for our search. The factors of 360 are:

1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 30, 36, 40, 45, 60, 72, 90, 120, 180, 360

We are looking for a pair of factors (y, x) from this list such that their difference is 66. We can systematically check the factors, starting with the smaller ones, and see if adding 66 to a factor results in another factor of 360. Alternatively, we can leverage the information from the prime factorization of the LCM to guide our search more efficiently.

If y = 1, then x = 1 + 66 = 67, which is not a factor of 360. If y = 2, then x = 2 + 66 = 68, which is not a factor of 360. If y = 3, then x = 3 + 66 = 69, which is not a factor of 360. …

This methodical process, although potentially time-consuming, guarantees that we explore all possibilities. However, we can refine our approach by considering the prime factorization insights we gained earlier.

Combining Insights: A Strategic Search

Let's revisit the prime factorization of 360 (2^3 * 3^2 * 5) and the equation x = y + 66. We know that both x and y must be factors of 360. Furthermore, we know that at least one of x or y must have 2^3 (which is 8) as a factor, at least one must have 3^2 (which is 9) as a factor, and at least one must have 5 as a factor. This knowledge enables us to strategically narrow our search.

We can start by looking for factors of 360 that have 8, 9, or 5 as factors. Then, we can check if adding 66 to such a factor results in another factor of 360. This approach is more efficient than checking all possible pairs of factors.

Consider the factor 24 (2^3 * 3). If y = 24, then x = 24 + 66 = 90. Let's check if 90 is a factor of 360. Indeed, 90 is a factor of 360 (90 = 2 * 3^2 * 5). Now, we need to verify if the LCM of 24 and 90 is 360.

Prime factorization of 24: 2^3 * 3 Prime factorization of 90: 2 * 3^2 * 5

LCM(24, 90) = 2^3 * 3^2 * 5 = 8 * 9 * 5 = 360

Thus, the pair (24, 90) satisfies both conditions: their difference is 66, and their LCM is 360.

The Solution: Numbers Revealed

Through a combination of prime factorization, understanding LCM properties, leveraging the difference equation, and systematic checking, we have successfully found the two natural numbers that meet the given criteria. The two natural numbers whose difference is 66 and whose least common multiple is 360 are 24 and 90.

In summary:

  • The two numbers are 24 and 90.
  • Their difference is 90 - 24 = 66.
  • Their LCM is LCM(24, 90) = 360.

This problem demonstrates the interconnectedness of various mathematical concepts and the power of combining different techniques to solve a problem. The solution not only provides the answer but also reinforces our understanding of number theory principles.

This exploration of two natural numbers with specific properties highlights the elegance and problem-solving capabilities within mathematics. By mastering fundamental concepts and employing strategic approaches, we can unravel seemingly complex puzzles and gain a deeper appreciation for the world of numbers.

This exercise illustrates the beauty of mathematics in revealing solutions to complex puzzles through systematic reasoning and the application of fundamental principles. The blend of algebraic manipulation, prime factorization, and logical deduction is a testament to the power of mathematical thinking.