Math Problem Statement

The lowest common multiple (LCM) of y and 120 is 360.

Find the smallest possible value of y .

Solution

We are given that the lowest common multiple (LCM) of yy and 120 is 360. We are tasked with finding the smallest possible value of yy.

Step 1: Prime Factorization of 120 and 360

First, we find the prime factorizations of 120 and 360.

  • 120=23×3×5120 = 2^3 \times 3 \times 5
  • 360=23×32×5360 = 2^3 \times 3^2 \times 5

Step 2: Use of LCM Formula

The formula for the LCM of two numbers is the product of the highest powers of all the prime factors that appear in the factorizations of both numbers.

We know: LCM(y,120)=360\text{LCM}(y, 120) = 360

This means that the prime factorization of yy must combine with the prime factorization of 120 to produce the prime factorization of 360.

Step 3: Analyze Prime Factors for yy

Since 360=23×32×5360 = 2^3 \times 3^2 \times 5 and 120=23×3×5120 = 2^3 \times 3 \times 5, we compare them to find out what factors yy must include:

  • For the prime factor 22, 120120 already has 232^3, and 360360 also has 232^3. Therefore, yy does not need any additional factors of 2.
  • For the prime factor 33, 120120 has 313^1, but 360360 has 323^2. This means that yy must include at least one more factor of 3 to contribute to the total of 323^2.
  • For the prime factor 55, 120120 already has 55, and 360360 also has 55, so yy does not need any additional factors of 5.

Thus, the smallest yy must have 313^1 as its prime factor to account for the missing factor of 3 in 120. Therefore, the smallest value of yy is: y=3y = 3

Final Answer:

The smallest possible value of yy is 3\boxed{3}.

Would you like a further breakdown or have any questions?

Here are 5 related questions for further exploration:

  1. What is the LCM of 18 and 24?
  2. How do you find the greatest common divisor (GCD) of two numbers?
  3. Can two numbers have the same LCM and GCD?
  4. What is the relation between LCM and GCD of two numbers?
  5. How do you find the LCM of three or more numbers?

Tip: The LCM can be helpful in problems involving synchronization of cycles or periodic events.

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Math Problem Analysis

Mathematical Concepts

Prime Factorization
LCM (Lowest Common Multiple)

Formulas

LCM(a, b) = Product of the highest powers of all prime factors

Theorems

LCM Theorem

Suitable Grade Level

Grades 6-8