Math Problem Statement

Find the smallest square number that is divisible by each of the numbers 16,18,24,28,30

Solution

To find the smallest square number divisible by 16, 18, 24, 28, and 30, we need to follow these steps:

  1. Prime Factorization: Find the prime factorization of each number.

    • 16=2416 = 2^4
    • 18=2×3218 = 2 \times 3^2
    • 24=23×324 = 2^3 \times 3
    • 28=22×728 = 2^2 \times 7
    • 30=2×3×530 = 2 \times 3 \times 5
  2. Least Common Multiple (LCM): Find the least common multiple (LCM) of the numbers by taking the highest powers of all prime factors appearing in the factorizations.

    • For 22: The highest power is 242^4 from 16.
    • For 33: The highest power is 323^2 from 18.
    • For 55: The highest power is 515^1 from 30.
    • For 77: The highest power is 717^1 from 28.

    Therefore, the LCM is:

    LCM=24×32×5×7=16×9×5×7\text{LCM} = 2^4 \times 3^2 \times 5 \times 7 = 16 \times 9 \times 5 \times 7

  3. Calculate the LCM: LCM=16×9×5×7=144×35=5040\text{LCM} = 16 \times 9 \times 5 \times 7 = 144 \times 35 = 5040

  4. Smallest Square Number: To find the smallest square number divisible by this LCM, every prime factor in the factorization of the LCM must be raised to an even power.

    • For 22: It is already 242^4, an even power.
    • For 33: It is 323^2, an even power.
    • For 55: It is 515^1, we need 525^2.
    • For 77: It is 717^1, we need 727^2.

    Therefore, the smallest square number divisible by all these numbers is: (24×32×52×72)=16×9×25×49(2^4 \times 3^2 \times 5^2 \times 7^2) = 16 \times 9 \times 25 \times 49

  5. Calculate the Square Number: Smallest square number=16×9×25×49=144×1225=176400\text{Smallest square number} = 16 \times 9 \times 25 \times 49 = 144 \times 1225 = 176400

Final Answer: The smallest square number that is divisible by 16, 18, 24, 28, and 30 is 176400.

Do you need more details or have any questions about this solution?

Here are 5 related questions for further practice:

  1. What is the smallest square number divisible by 12, 15, and 20?
  2. How do you find the LCM of three numbers using their prime factorizations?
  3. What is the smallest square number divisible by 8, 14, 21, and 35?
  4. How do you calculate the square root of a large number like 176400?
  5. What are the steps to determine if a given number is a perfect square?

Tip: Always ensure each prime factor in the LCM has an even exponent to find the smallest square number.

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Math Problem Analysis

Mathematical Concepts

Number Theory
Prime Factorization
Least Common Multiple (LCM)
Square Numbers

Formulas

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Theorems

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Suitable Grade Level

Grades 10-12