LCM of 20 and 30

LCM of 20 and 30 is the smallest number among all common multiples of 20 and 30. The first few multiples of 20 and 30 are (20, 40, 60, 80, . . . ) and (30, 60, 90, 120, 150, 180, . . . ) respectively. There are 3 commonly used methods to find LCM of 20 and 30 - by listing multiples, by division method, and by prime factorization.

Answer: LCM of 20 and 30 is 60.

Explanation:

The LCM of two non-zero integers, x(20) and y(30), is the smallest positive integer m(60) that is divisible by both x(20) and y(30) without any remainder.

Let's look at the different methods for finding the LCM of 20 and 30.

• By Listing Multiples
• By Division Method
• By Prime Factorization Method

LCM of 20 and 30 by Listing Multiples

To calculate the LCM of 20 and 30 by listing out the common multiples, we can follow the given below steps:

• Step 1: List a few multiples of 20 (20, 40, 60, 80, . . . ) and 30 (30, 60, 90, 120, 150, 180, . . . . )
• Step 2: The common multiples from the multiples of 20 and 30 are 60, 120, . . .
• Step 3: The smallest common multiple of 20 and 30 is 60.

∴ The least common multiple of 20 and 30 = 60.

LCM of 20 and 30 by Division Method

To calculate the LCM of 20 and 30 by the division method, we will divide the numbers(20, 30) by their prime factors (preferably common). The product of these divisors gives the LCM of 20 and 30.

• Step 1: Find the smallest prime number that is a factor of at least one of the numbers, 20 and 30. Write this prime number(2) on the left of the given numbers(20 and 30), separated as per the ladder arrangement.
• Step 2: If any of the given numbers (20, 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 20 and 30 is the product of all prime numbers on the left, i.e. LCM(20, 30) by division method = 2 × 2 × 3 × 5 = 60.

LCM of 20 and 30 by Prime Factorization

Prime factorization of 20 and 30 is (2 × 2 × 5) = 2² × 5¹ and (2 × 3 × 5) = 2¹ × 3¹ × 5¹ respectively. LCM of 20 and 30 can be obtained by multiplying prime factors raised to their respective highest power, i.e. 2² × 3¹ × 5¹ = 60.
Hence, the LCM of 20 and 30 by prime factorization is 60.

☛ Also Check:

• LCM of 45 and 75 - 225
• LCM of 54 and 60 - 540
• LCM of 12, 16 and 24 - 48
• LCM of 8 and 42 - 168
• LCM of 42 and 70 - 210
• LCM of 24 and 32 - 96
• LCM of 36 and 40 - 360

FAQs on LCM of 20 and 30

What is the LCM of 20 and 30?

The LCM of 20 and 30 is 60. To find the least common multiple of 20 and 30, we need to find the multiples of 20 and 30 (multiples of 20 = 20, 40, 60, 80; multiples of 30 = 30, 60, 90, 120) and choose the smallest multiple that is exactly divisible by 20 and 30, i.e., 60.

If the LCM of 30 and 20 is 60, Find its GCF.

LCM(30, 20) × GCF(30, 20) = 30 × 20
Since the LCM of 30 and 20 = 60
⇒ 60 × GCF(30, 20) = 600
Therefore, the GCF (greatest common factor) = 600/60 = 10.

What are the Methods to Find LCM of 20 and 30?

The commonly used methods to find the LCM of 20 and 30 are:

• Listing Multiples
• Division Method
• Prime Factorization Method

What is the Least Perfect Square Divisible by 20 and 30?

The least number divisible by 20 and 30 = LCM(20, 30)
LCM of 20 and 30 = 2 × 2 × 3 × 5 [Incomplete pair(s): 3, 5]
⇒ Least perfect square divisible by each 20 and 30 = LCM(20, 30) × 3 × 5 = 900 [Square root of 900 = √900 = ±30]
Therefore, 900 is the required number.

Which of the following is the LCM of 20 and 30? 60, 10, 36, 40

The value of LCM of 20, 30 is the smallest common multiple of 20 and 30. The number satisfying the given condition is 60.