LCM of 56 and 72
LCM of 56 and 72 is the smallest number among all common multiples of 56 and 72. The first few multiples of 56 and 72 are (56, 112, 168, 224, 280, . . . ) and (72, 144, 216, 288, 360, . . . ) respectively. There are 3 commonly used methods to find LCM of 56 and 72 - by division method, by listing multiples, and by prime factorization.
1. | LCM of 56 and 72 |
2. | List of Methods |
3. | Solved Examples |
4. | FAQs |
What is the LCM of 56 and 72?
Answer: LCM of 56 and 72 is 504.
Explanation:
The LCM of two non-zero integers, x(56) and y(72), is the smallest positive integer m(504) that is divisible by both x(56) and y(72) without any remainder.
Methods to Find LCM of 56 and 72
The methods to find the LCM of 56 and 72 are explained below.
- By Division Method
- By Prime Factorization Method
- By Listing Multiples
LCM of 56 and 72 by Division Method
To calculate the LCM of 56 and 72 by the division method, we will divide the numbers(56, 72) by their prime factors (preferably common). The product of these divisors gives the LCM of 56 and 72.
- Step 1: Find the smallest prime number that is a factor of at least one of the numbers, 56 and 72. Write this prime number(2) on the left of the given numbers(56 and 72), separated as per the ladder arrangement.
- Step 2: If any of the given numbers (56, 72) 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 56 and 72 is the product of all prime numbers on the left, i.e. LCM(56, 72) by division method = 2 × 2 × 2 × 3 × 3 × 7 = 504.
LCM of 56 and 72 by Prime Factorization
Prime factorization of 56 and 72 is (2 × 2 × 2 × 7) = 23 × 71 and (2 × 2 × 2 × 3 × 3) = 23 × 32 respectively. LCM of 56 and 72 can be obtained by multiplying prime factors raised to their respective highest power, i.e. 23 × 32 × 71 = 504.
Hence, the LCM of 56 and 72 by prime factorization is 504.
LCM of 56 and 72 by Listing Multiples
To calculate the LCM of 56 and 72 by listing out the common multiples, we can follow the given below steps:
- Step 1: List a few multiples of 56 (56, 112, 168, 224, 280, . . . ) and 72 (72, 144, 216, 288, 360, . . . . )
- Step 2: The common multiples from the multiples of 56 and 72 are 504, 1008, . . .
- Step 3: The smallest common multiple of 56 and 72 is 504.
∴ The least common multiple of 56 and 72 = 504.
☛ Also Check:
- LCM of 45 and 120 - 360
- LCM of 7 and 16 - 112
- LCM of 9 and 45 - 45
- LCM of 7 and 7 - 7
- LCM of 54 and 90 - 270
- LCM of 6, 8 and 12 - 24
- LCM of 10 and 100 - 100
LCM of 56 and 72 Examples
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Example 1: Verify the relationship between GCF and LCM of 56 and 72.
Solution:
The relation between GCF and LCM of 56 and 72 is given as,
LCM(56, 72) × GCF(56, 72) = Product of 56, 72
Prime factorization of 56 and 72 is given as, 56 = (2 × 2 × 2 × 7) = 23 × 71 and 72 = (2 × 2 × 2 × 3 × 3) = 23 × 32
LCM(56, 72) = 504
GCF(56, 72) = 8
LHS = LCM(56, 72) × GCF(56, 72) = 504 × 8 = 4032
RHS = Product of 56, 72 = 56 × 72 = 4032
⇒ LHS = RHS = 4032
Hence, verified. -
Example 2: Find the smallest number that is divisible by 56 and 72 exactly.
Solution:
The smallest number that is divisible by 56 and 72 exactly is their LCM.
⇒ Multiples of 56 and 72:- Multiples of 56 = 56, 112, 168, 224, 280, 336, 392, 448, 504, . . . .
- Multiples of 72 = 72, 144, 216, 288, 360, 432, 504, . . . .
Therefore, the LCM of 56 and 72 is 504.
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Example 3: The GCD and LCM of two numbers are 8 and 504 respectively. If one number is 72, find the other number.
Solution:
Let the other number be y.
∵ GCD × LCM = 72 × y
⇒ y = (GCD × LCM)/72
⇒ y = (8 × 504)/72
⇒ y = 56
Therefore, the other number is 56.
FAQs on LCM of 56 and 72
What is the LCM of 56 and 72?
The LCM of 56 and 72 is 504. To find the least common multiple of 56 and 72, we need to find the multiples of 56 and 72 (multiples of 56 = 56, 112, 168, 224 . . . . 504; multiples of 72 = 72, 144, 216, 288 . . . . 504) and choose the smallest multiple that is exactly divisible by 56 and 72, i.e., 504.
Which of the following is the LCM of 56 and 72? 3, 24, 504, 45
The value of LCM of 56, 72 is the smallest common multiple of 56 and 72. The number satisfying the given condition is 504.
If the LCM of 72 and 56 is 504, Find its GCF.
LCM(72, 56) × GCF(72, 56) = 72 × 56
Since the LCM of 72 and 56 = 504
⇒ 504 × GCF(72, 56) = 4032
Therefore, the greatest common factor (GCF) = 4032/504 = 8.
What is the Least Perfect Square Divisible by 56 and 72?
The least number divisible by 56 and 72 = LCM(56, 72)
LCM of 56 and 72 = 2 × 2 × 2 × 3 × 3 × 7 [Incomplete pair(s): 2, 7]
⇒ Least perfect square divisible by each 56 and 72 = LCM(56, 72) × 2 × 7 = 7056 [Square root of 7056 = √7056 = ±84]
Therefore, 7056 is the required number.
How to Find the LCM of 56 and 72 by Prime Factorization?
To find the LCM of 56 and 72 using prime factorization, we will find the prime factors, (56 = 2 × 2 × 2 × 7) and (72 = 2 × 2 × 2 × 3 × 3). LCM of 56 and 72 is the product of prime factors raised to their respective highest exponent among the numbers 56 and 72.
⇒ LCM of 56, 72 = 23 × 32 × 71 = 504.
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