LCM of 18, 24, and 30
LCM of 18, 24, and 30 is the smallest number among all common multiples of 18, 24, and 30. The first few multiples of 18, 24, and 30 are (18, 36, 54, 72, 90 . . .), (24, 48, 72, 96, 120 . . .), and (30, 60, 90, 120, 150 . . .) respectively. There are 3 commonly used methods to find LCM of 18, 24, 30 - by division method, by listing multiples, and by prime factorization.
1. | LCM of 18, 24, and 30 |
2. | List of Methods |
3. | Solved Examples |
4. | FAQs |
What is the LCM of 18, 24, and 30?
Answer: LCM of 18, 24, and 30 is 360.
Explanation:
The LCM of three non-zero integers, a(18), b(24), and c(30), is the smallest positive integer m(360) that is divisible by a(18), b(24), and c(30) without any remainder.
Methods to Find LCM of 18, 24, and 30
The methods to find the LCM of 18, 24, and 30 are explained below.
- By Prime Factorization Method
- By Division Method
- By Listing Multiples
LCM of 18, 24, and 30 by Prime Factorization
Prime factorization of 18, 24, and 30 is (2 × 3 × 3) = 21 × 32, (2 × 2 × 2 × 3) = 23 × 31, and (2 × 3 × 5) = 21 × 31 × 51 respectively. LCM of 18, 24, and 30 can be obtained by multiplying prime factors raised to their respective highest power, i.e. 23 × 32 × 51 = 360.
Hence, the LCM of 18, 24, and 30 by prime factorization is 360.
LCM of 18, 24, and 30 by Division Method
To calculate the LCM of 18, 24, and 30 by the division method, we will divide the numbers(18, 24, 30) by their prime factors (preferably common). The product of these divisors gives the LCM of 18, 24, and 30.
- Step 1: Find the smallest prime number that is a factor of at least one of the numbers, 18, 24, and 30. Write this prime number(2) on the left of the given numbers(18, 24, and 30), separated as per the ladder arrangement.
- Step 2: If any of the given numbers (18, 24, 30) is a multiple of 2, divide it by 2 and write the quotient below it. Bring down any number that is not divisible by the prime number.
- Step 3: Continue the steps until only 1s are left in the last row.
The LCM of 18, 24, and 30 is the product of all prime numbers on the left, i.e. LCM(18, 24, 30) by division method = 2 × 2 × 2 × 3 × 3 × 5 = 360.
LCM of 18, 24, and 30 by Listing Multiples
To calculate the LCM of 18, 24, 30 by listing out the common multiples, we can follow the given below steps:
- Step 1: List a few multiples of 18 (18, 36, 54, 72, 90 . . .), 24 (24, 48, 72, 96, 120 . . .), and 30 (30, 60, 90, 120, 150 . . .).
- Step 2: The common multiples from the multiples of 18, 24, and 30 are 360, 720, . . .
- Step 3: The smallest common multiple of 18, 24, and 30 is 360.
∴ The least common multiple of 18, 24, and 30 = 360.
☛ Also Check:
- LCM of 3, 5 and 11 - 165
- LCM of 21 and 22 - 462
- LCM of 35, 12 and 70 - 420
- LCM of 120 and 144 - 720
- LCM of 6 and 12 - 12
- LCM of 5, 8 and 15 - 120
- LCM of 2 and 12 - 12
LCM of 18, 24, and 30 Examples
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Example 1: Calculate the LCM of 18, 24, and 30 using the GCD of the given numbers.
Solution:
Prime factorization of 18, 24, 30:
- 18 = 21 × 32
- 24 = 23 × 31
- 30 = 21 × 31 × 51
Therefore, GCD(18, 24) = 6, GCD(24, 30) = 6, GCD(18, 30) = 6, GCD(18, 24, 30) = 6
We know,
LCM(18, 24, 30) = [(18 × 24 × 30) × GCD(18, 24, 30)]/[GCD(18, 24) × GCD(24, 30) × GCD(18, 30)]
LCM(18, 24, 30) = (12960 × 6)/(6 × 6 × 6) = 360
⇒LCM(18, 24, 30) = 360 -
Example 2: Find the smallest number that is divisible by 18, 24, 30 exactly.
Solution:
The value of LCM(18, 24, 30) will be the smallest number that is exactly divisible by 18, 24, and 30.
⇒ Multiples of 18, 24, and 30:- Multiples of 18 = 18, 36, 54, 72, 90, 108, 126, 144, 162, 180, . . . ., 288, 306, 324, 342, 360, . . . .
- Multiples of 24 = 24, 48, 72, 96, 120, 144, 168, 192, 216, 240, . . . ., 312, 336, 360, . . . .
- Multiples of 30 = 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, . . . ., 240, 270, 300, 330, 360, . . . .
Therefore, the LCM of 18, 24, and 30 is 360.
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Example 3: Verify the relationship between the GCD and LCM of 18, 24, and 30.
Solution:
The relation between GCD and LCM of 18, 24, and 30 is given as,
LCM(18, 24, 30) = [(18 × 24 × 30) × GCD(18, 24, 30)]/[GCD(18, 24) × GCD(24, 30) × GCD(18, 30)]
⇒ Prime factorization of 18, 24 and 30:- 18 = 21 × 32
- 24 = 23 × 31
- 30 = 21 × 31 × 51
∴ GCD of (18, 24), (24, 30), (18, 30) and (18, 24, 30) = 6, 6, 6 and 6 respectively.
Now, LHS = LCM(18, 24, 30) = 360.
And, RHS = [(18 × 24 × 30) × GCD(18, 24, 30)]/[GCD(18, 24) × GCD(24, 30) × GCD(18, 30)] = [(12960) × 6]/[6 × 6 × 6] = 360
LHS = RHS = 360.
Hence verified.
FAQs on LCM of 18, 24, and 30
What is the LCM of 18, 24, and 30?
The LCM of 18, 24, and 30 is 360. To find the LCM of 18, 24, and 30, we need to find the multiples of 18, 24, and 30 (multiples of 18 = 18, 36, 54, 72 . . . . 360 . . . . ; multiples of 24 = 24, 48, 72, 96 . . . . 360 . . . . ; multiples of 30 = 30, 60, 90, 120 . . . . 360 . . . . ) and choose the smallest multiple that is exactly divisible by 18, 24, and 30, i.e., 360.
Which of the following is the LCM of 18, 24, and 30? 16, 100, 25, 360
The value of LCM of 18, 24, 30 is the smallest common multiple of 18, 24, and 30. The number satisfying the given condition is 360.
How to Find the LCM of 18, 24, and 30 by Prime Factorization?
To find the LCM of 18, 24, and 30 using prime factorization, we will find the prime factors, (18 = 21 × 32), (24 = 23 × 31), and (30 = 21 × 31 × 51). LCM of 18, 24, and 30 is the product of prime factors raised to their respective highest exponent among the numbers 18, 24, and 30.
⇒ LCM of 18, 24, 30 = 23 × 32 × 51 = 360.
What are the Methods to Find LCM of 18, 24, 30?
The commonly used methods to find the LCM of 18, 24, 30 are:
- Prime Factorization Method
- Division Method
- Listing Multiples
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