LCM of 56 and 70
LCM of 56 and 70 is the smallest number among all common multiples of 56 and 70. The first few multiples of 56 and 70 are (56, 112, 168, 224, 280, . . . ) and (70, 140, 210, 280, 350, . . . ) respectively. There are 3 commonly used methods to find LCM of 56 and 70 - by listing multiples, by prime factorization, and by division method.
1. | LCM of 56 and 70 |
2. | List of Methods |
3. | Solved Examples |
4. | FAQs |
What is the LCM of 56 and 70?
Answer: LCM of 56 and 70 is 280.
Explanation:
The LCM of two non-zero integers, x(56) and y(70), is the smallest positive integer m(280) that is divisible by both x(56) and y(70) without any remainder.
Methods to Find LCM of 56 and 70
The methods to find the LCM of 56 and 70 are explained below.
- By Listing Multiples
- By Division Method
- By Prime Factorization Method
LCM of 56 and 70 by Listing Multiples
To calculate the LCM of 56 and 70 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 70 (70, 140, 210, 280, 350, . . . . )
- Step 2: The common multiples from the multiples of 56 and 70 are 280, 560, . . .
- Step 3: The smallest common multiple of 56 and 70 is 280.
∴ The least common multiple of 56 and 70 = 280.
LCM of 56 and 70 by Division Method
To calculate the LCM of 56 and 70 by the division method, we will divide the numbers(56, 70) by their prime factors (preferably common). The product of these divisors gives the LCM of 56 and 70.
- Step 1: Find the smallest prime number that is a factor of at least one of the numbers, 56 and 70. Write this prime number(2) on the left of the given numbers(56 and 70), separated as per the ladder arrangement.
- Step 2: If any of the given numbers (56, 70) 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 70 is the product of all prime numbers on the left, i.e. LCM(56, 70) by division method = 2 × 2 × 2 × 5 × 7 = 280.
LCM of 56 and 70 by Prime Factorization
Prime factorization of 56 and 70 is (2 × 2 × 2 × 7) = 23 × 71 and (2 × 5 × 7) = 21 × 51 × 71 respectively. LCM of 56 and 70 can be obtained by multiplying prime factors raised to their respective highest power, i.e. 23 × 51 × 71 = 280.
Hence, the LCM of 56 and 70 by prime factorization is 280.
☛ Also Check:
- LCM of 5 and 10 - 10
- LCM of 35, 12 and 70 - 420
- LCM of 35 and 60 - 420
- LCM of 6, 8 and 12 - 24
- LCM of 3 and 13 - 39
- LCM of 6, 72 and 120 - 360
- LCM of 30 and 35 - 210
LCM of 56 and 70 Examples
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Example 1: Verify the relationship between GCF and LCM of 56 and 70.
Solution:
The relation between GCF and LCM of 56 and 70 is given as,
LCM(56, 70) × GCF(56, 70) = Product of 56, 70
Prime factorization of 56 and 70 is given as, 56 = (2 × 2 × 2 × 7) = 23 × 71 and 70 = (2 × 5 × 7) = 21 × 51 × 71
LCM(56, 70) = 280
GCF(56, 70) = 14
LHS = LCM(56, 70) × GCF(56, 70) = 280 × 14 = 3920
RHS = Product of 56, 70 = 56 × 70 = 3920
⇒ LHS = RHS = 3920
Hence, verified. -
Example 2: Find the smallest number that is divisible by 56 and 70 exactly.
Solution:
The smallest number that is divisible by 56 and 70 exactly is their LCM.
⇒ Multiples of 56 and 70:- Multiples of 56 = 56, 112, 168, 224, 280, . . . .
- Multiples of 70 = 70, 140, 210, 280, 350, . . . .
Therefore, the LCM of 56 and 70 is 280.
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Example 3: The product of two numbers is 3920. If their GCD is 14, what is their LCM?
Solution:
Given: GCD = 14
product of numbers = 3920
∵ LCM × GCD = product of numbers
⇒ LCM = Product/GCD = 3920/14
Therefore, the LCM is 280.
The probable combination for the given case is LCM(56, 70) = 280.
FAQs on LCM of 56 and 70
What is the LCM of 56 and 70?
The LCM of 56 and 70 is 280. To find the LCM of 56 and 70, we need to find the multiples of 56 and 70 (multiples of 56 = 56, 112, 168, 224 . . . . 280; multiples of 70 = 70, 140, 210, 280) and choose the smallest multiple that is exactly divisible by 56 and 70, i.e., 280.
What is the Relation Between GCF and LCM of 56, 70?
The following equation can be used to express the relation between GCF and LCM of 56 and 70, i.e. GCF × LCM = 56 × 70.
Which of the following is the LCM of 56 and 70? 20, 280, 36, 42
The value of LCM of 56, 70 is the smallest common multiple of 56 and 70. The number satisfying the given condition is 280.
If the LCM of 70 and 56 is 280, Find its GCF.
LCM(70, 56) × GCF(70, 56) = 70 × 56
Since the LCM of 70 and 56 = 280
⇒ 280 × GCF(70, 56) = 3920
Therefore, the greatest common factor (GCF) = 3920/280 = 14.
What is the Least Perfect Square Divisible by 56 and 70?
The least number divisible by 56 and 70 = LCM(56, 70)
LCM of 56 and 70 = 2 × 2 × 2 × 5 × 7 [Incomplete pair(s): 2, 5, 7]
⇒ Least perfect square divisible by each 56 and 70 = LCM(56, 70) × 2 × 5 × 7 = 19600 [Square root of 19600 = √19600 = ±140]
Therefore, 19600 is the required number.
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