A day full of math games & activities. Find one near you.

LCM of 6, 72, and 120

LCM of 6, 72, and 120 is the smallest number among all common multiples of 6, 72, and 120. The first few multiples of 6, 72, and 120 are (6, 12, 18, 24, 30 . . .), (72, 144, 216, 288, 360 . . .), and (120, 240, 360, 480, 600 . . .) respectively. There are 3 commonly used methods to find LCM of 6, 72, 120 - by prime factorization, by listing multiples, and by division method.

1.	LCM of 6, 72, and 120
2.	List of Methods
3.	Solved Examples
4.	FAQs

What is the LCM of 6, 72, and 120?

Answer: LCM of 6, 72, and 120 is 360.

Explanation:

The LCM of three non-zero integers, a(6), b(72), and c(120), is the smallest positive integer m(360) that is divisible by a(6), b(72), and c(120) without any remainder.

Methods to Find LCM of 6, 72, and 120

Let's look at the different methods for finding the LCM of 6, 72, and 120.

By Division Method
By Prime Factorization Method
By Listing Multiples

LCM of 6, 72, and 120 by Division Method

To calculate the LCM of 6, 72, and 120 by the division method, we will divide the numbers(6, 72, 120) by their prime factors (preferably common). The product of these divisors gives the LCM of 6, 72, and 120.

Step 1: Find the smallest prime number that is a factor of at least one of the numbers, 6, 72, and 120. Write this prime number(2) on the left of the given numbers(6, 72, and 120), separated as per the ladder arrangement.
Step 2: If any of the given numbers (6, 72, 120) 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 6, 72, and 120 is the product of all prime numbers on the left, i.e. LCM(6, 72, 120) by division method = 2 × 2 × 2 × 3 × 3 × 5 = 360.

LCM of 6, 72, and 120 by Prime Factorization

Prime factorization of 6, 72, and 120 is (2 × 3) = 2¹ × 3¹, (2 × 2 × 2 × 3 × 3) = 2³ × 3², and (2 × 2 × 2 × 3 × 5) = 2³ × 3¹ × 5¹ respectively. LCM of 6, 72, and 120 can be obtained by multiplying prime factors raised to their respective highest power, i.e. 2³ × 3² × 5¹ = 360.
Hence, the LCM of 6, 72, and 120 by prime factorization is 360.

LCM of 6, 72, and 120 by Listing Multiples

To calculate the LCM of 6, 72, 120 by listing out the common multiples, we can follow the given below steps:

Step 1: List a few multiples of 6 (6, 12, 18, 24, 30 . . .), 72 (72, 144, 216, 288, 360 . . .), and 120 (120, 240, 360, 480, 600 . . .).
Step 2: The common multiples from the multiples of 6, 72, and 120 are 360, 720, . . .
Step 3: The smallest common multiple of 6, 72, and 120 is 360.

∴ The least common multiple of 6, 72, and 120 = 360.

☛ Also Check:

LCM of 6, 72, and 120 Examples

Example 1: Calculate the LCM of 6, 72, and 120 using the GCD of the given numbers.

Solution:

Prime factorization of 6, 72, 120:
- 6 = 2¹ × 3¹
- 72 = 2³ × 3²
- 120 = 2³ × 3¹ × 5¹
Therefore, GCD(6, 72) = 6, GCD(72, 120) = 24, GCD(6, 120) = 6, GCD(6, 72, 120) = 6
We know,
LCM(6, 72, 120) = [(6 × 72 × 120) × GCD(6, 72, 120)]/[GCD(6, 72) × GCD(72, 120) × GCD(6, 120)]
LCM(6, 72, 120) = (51840 × 6)/(6 × 24 × 6) = 360
⇒LCM(6, 72, 120) = 360
Example 2: Verify the relationship between the GCD and LCM of 6, 72, and 120.

Solution:

The relation between GCD and LCM of 6, 72, and 120 is given as,
LCM(6, 72, 120) = [(6 × 72 × 120) × GCD(6, 72, 120)]/[GCD(6, 72) × GCD(72, 120) × GCD(6, 120)]
⇒ Prime factorization of 6, 72 and 120:
- 6 = 2¹ × 3¹
- 72 = 2³ × 3²
- 120 = 2³ × 3¹ × 5¹
∴ GCD of (6, 72), (72, 120), (6, 120) and (6, 72, 120) = 6, 24, 6 and 6 respectively.
Now, LHS = LCM(6, 72, 120) = 360.
And, RHS = [(6 × 72 × 120) × GCD(6, 72, 120)]/[GCD(6, 72) × GCD(72, 120) × GCD(6, 120)] = [(51840) × 6]/[6 × 24 × 6] = 360
LHS = RHS = 360.
Hence verified.
Example 3: Find the smallest number that is divisible by 6, 72, 120 exactly.

Solution:

The value of LCM(6, 72, 120) will be the smallest number that is exactly divisible by 6, 72, and 120.
⇒ Multiples of 6, 72, and 120:
- Multiples of 6 = 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, . . . ., 336, 342, 348, 354, 360, . . . .
- Multiples of 72 = 72, 144, 216, 288, 360, 432, 504, 576, 648, 720, . . . ., 144, 216, 288, 360, . . . .
- Multiples of 120 = 120, 240, 360, 480, 600, 720, 840, 960, 1080, 1200, . . . ., -120, 0, 120, 240, 360, . . . .
Therefore, the LCM of 6, 72, and 120 is 360.

go to slide go to slide go to slide

Ready to see the world through math’s eyes?

Math is at the core of everything we do. Enjoy solving real-world math problems in live classes and become an expert at everything.

Book a Free Trial Class

FAQs on LCM of 6, 72, and 120

What is the LCM of 6, 72, and 120?

The LCM of 6, 72, and 120 is 360. To find the LCM of 6, 72, and 120, we need to find the multiples of 6, 72, and 120 (multiples of 6 = 6, 12, 18, 24 . . . . 360 . . . . ; multiples of 72 = 72, 144, 216, 288 . . . . 360 . . . . ; multiples of 120 = 120, 240, 360, 480 . . . .) and choose the smallest multiple that is exactly divisible by 6, 72, and 120, i.e., 360.

Which of the following is the LCM of 6, 72, and 120? 360, 21, 110, 3

The value of LCM of 6, 72, 120 is the smallest common multiple of 6, 72, and 120. The number satisfying the given condition is 360.

What are the Methods to Find LCM of 6, 72, 120?

The commonly used methods to find the LCM of 6, 72, 120 are:

Division Method
Listing Multiples
Prime Factorization Method

What is the Relation Between GCF and LCM of 6, 72, 120?

The following equation can be used to express the relation between GCF and LCM of 6, 72, 120, i.e. LCM(6, 72, 120) = [(6 × 72 × 120) × GCF(6, 72, 120)]/[GCF(6, 72) × GCF(72, 120) × GCF(6, 120)].

Download FREE Study Materials

LCM and GCF

Math worksheets and
visual curriculum