LCM of 30, 36, and 40
LCM of 30, 36, and 40 is the smallest number among all common multiples of 30, 36, and 40. The first few multiples of 30, 36, and 40 are (30, 60, 90, 120, 150 . . .), (36, 72, 108, 144, 180 . . .), and (40, 80, 120, 160, 200 . . .) respectively. There are 3 commonly used methods to find LCM of 30, 36, 40 - by prime factorization, by listing multiples, and by division method.
1. | LCM of 30, 36, and 40 |
2. | List of Methods |
3. | Solved Examples |
4. | FAQs |
What is the LCM of 30, 36, and 40?
Answer: LCM of 30, 36, and 40 is 360.
Explanation:
The LCM of three non-zero integers, a(30), b(36), and c(40), is the smallest positive integer m(360) that is divisible by a(30), b(36), and c(40) without any remainder.
Methods to Find LCM of 30, 36, and 40
Let's look at the different methods for finding the LCM of 30, 36, and 40.
- By Listing Multiples
- By Prime Factorization Method
- By Division Method
LCM of 30, 36, and 40 by Listing Multiples
To calculate the LCM of 30, 36, 40 by listing out the common multiples, we can follow the given below steps:
- Step 1: List a few multiples of 30 (30, 60, 90, 120, 150 . . .), 36 (36, 72, 108, 144, 180 . . .), and 40 (40, 80, 120, 160, 200 . . .).
- Step 2: The common multiples from the multiples of 30, 36, and 40 are 360, 720, . . .
- Step 3: The smallest common multiple of 30, 36, and 40 is 360.
∴ The least common multiple of 30, 36, and 40 = 360.
LCM of 30, 36, and 40 by Prime Factorization
Prime factorization of 30, 36, and 40 is (2 × 3 × 5) = 21 × 31 × 51, (2 × 2 × 3 × 3) = 22 × 32, and (2 × 2 × 2 × 5) = 23 × 51 respectively. LCM of 30, 36, and 40 can be obtained by multiplying prime factors raised to their respective highest power, i.e. 23 × 32 × 51 = 360.
Hence, the LCM of 30, 36, and 40 by prime factorization is 360.
LCM of 30, 36, and 40 by Division Method
To calculate the LCM of 30, 36, and 40 by the division method, we will divide the numbers(30, 36, 40) by their prime factors (preferably common). The product of these divisors gives the LCM of 30, 36, and 40.
- Step 1: Find the smallest prime number that is a factor of at least one of the numbers, 30, 36, and 40. Write this prime number(2) on the left of the given numbers(30, 36, and 40), separated as per the ladder arrangement.
- Step 2: If any of the given numbers (30, 36, 40) 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 30, 36, and 40 is the product of all prime numbers on the left, i.e. LCM(30, 36, 40) by division method = 2 × 2 × 2 × 3 × 3 × 5 = 360.
☛ Also Check:
- LCM of 5 and 12 - 60
- LCM of 25 and 35 - 175
- LCM of 75 and 100 - 300
- LCM of 10 and 50 - 50
- LCM of 15, 25 and 30 - 150
- LCM of 5 and 13 - 65
- LCM of 120 and 144 - 720
LCM of 30, 36, and 40 Examples
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Example 1: Find the smallest number that is divisible by 30, 36, 40 exactly.
Solution:
The smallest number that is divisible by 30, 36, and 40 exactly is their LCM.
⇒ Multiples of 30, 36, and 40:- Multiples of 30 = 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330, 360, . . . .
- Multiples of 36 = 36, 72, 108, 144, 180, 216, 252, 288, 324, 360, . . . .
- Multiples of 40 = 40, 80, 120, 160, 200, 240, 280, 320, 360, . . . .
Therefore, the LCM of 30, 36, and 40 is 360.
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Example 2: Verify the relationship between the GCD and LCM of 30, 36, and 40.
Solution:
The relation between GCD and LCM of 30, 36, and 40 is given as,
LCM(30, 36, 40) = [(30 × 36 × 40) × GCD(30, 36, 40)]/[GCD(30, 36) × GCD(36, 40) × GCD(30, 40)]
⇒ Prime factorization of 30, 36 and 40:- 30 = 21 × 31 × 51
- 36 = 22 × 32
- 40 = 23 × 51
∴ GCD of (30, 36), (36, 40), (30, 40) and (30, 36, 40) = 6, 4, 10 and 2 respectively.
Now, LHS = LCM(30, 36, 40) = 360.
And, RHS = [(30 × 36 × 40) × GCD(30, 36, 40)]/[GCD(30, 36) × GCD(36, 40) × GCD(30, 40)] = [(43200) × 2]/[6 × 4 × 10] = 360
LHS = RHS = 360.
Hence verified. -
Example 3: Calculate the LCM of 30, 36, and 40 using the GCD of the given numbers.
Solution:
Prime factorization of 30, 36, 40:
- 30 = 21 × 31 × 51
- 36 = 22 × 32
- 40 = 23 × 51
Therefore, GCD(30, 36) = 6, GCD(36, 40) = 4, GCD(30, 40) = 10, GCD(30, 36, 40) = 2
We know,
LCM(30, 36, 40) = [(30 × 36 × 40) × GCD(30, 36, 40)]/[GCD(30, 36) × GCD(36, 40) × GCD(30, 40)]
LCM(30, 36, 40) = (43200 × 2)/(6 × 4 × 10) = 360
⇒LCM(30, 36, 40) = 360
FAQs on LCM of 30, 36, and 40
What is the LCM of 30, 36, and 40?
The LCM of 30, 36, and 40 is 360. To find the LCM of 30, 36, and 40, we need to find the multiples of 30, 36, and 40 (multiples of 30 = 30, 60, 90, 120 . . . . 360 . . . . ; multiples of 36 = 36, 72, 108, 144 . . . . 360 . . . . ; multiples of 40 = 40, 80, 120, 160 . . . . 360 . . . . ) and choose the smallest multiple that is exactly divisible by 30, 36, and 40, i.e., 360.
What is the Least Perfect Square Divisible by 30, 36, and 40?
The least number divisible by 30, 36, and 40 = LCM(30, 36, 40)
LCM of 30, 36, and 40 = 2 × 2 × 2 × 3 × 3 × 5 [Incomplete pair(s): 2, 5]
⇒ Least perfect square divisible by each 30, 36, and 40 = LCM(30, 36, 40) × 2 × 5 = 3600 [Square root of 3600 = √3600 = ±60]
Therefore, 3600 is the required number.
How to Find the LCM of 30, 36, and 40 by Prime Factorization?
To find the LCM of 30, 36, and 40 using prime factorization, we will find the prime factors, (30 = 21 × 31 × 51), (36 = 22 × 32), and (40 = 23 × 51). LCM of 30, 36, and 40 is the product of prime factors raised to their respective highest exponent among the numbers 30, 36, and 40.
⇒ LCM of 30, 36, 40 = 23 × 32 × 51 = 360.
What is the Relation Between GCF and LCM of 30, 36, 40?
The following equation can be used to express the relation between GCF and LCM of 30, 36, 40, i.e. LCM(30, 36, 40) = [(30 × 36 × 40) × GCF(30, 36, 40)]/[GCF(30, 36) × GCF(36, 40) × GCF(30, 40)].
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