LCM of 9 and 10
LCM of 9 and 10 is the smallest number among all common multiples of 9 and 10. The first few multiples of 9 and 10 are (9, 18, 27, 36, 45, 54, 63, . . . ) and (10, 20, 30, 40, . . . ) respectively. There are 3 commonly used methods to find LCM of 9 and 10 - by prime factorization, by division method, and by listing multiples.
1. | LCM of 9 and 10 |
2. | List of Methods |
3. | Solved Examples |
4. | FAQs |
What is the LCM of 9 and 10?
Answer: LCM of 9 and 10 is 90.
Explanation:
The LCM of two non-zero integers, x(9) and y(10), is the smallest positive integer m(90) that is divisible by both x(9) and y(10) without any remainder.
Methods to Find LCM of 9 and 10
Let's look at the different methods for finding the LCM of 9 and 10.
- By Prime Factorization Method
- By Listing Multiples
- By Division Method
LCM of 9 and 10 by Prime Factorization
Prime factorization of 9 and 10 is (3 × 3) = 32 and (2 × 5) = 21 × 51 respectively. LCM of 9 and 10 can be obtained by multiplying prime factors raised to their respective highest power, i.e. 21 × 32 × 51 = 90.
Hence, the LCM of 9 and 10 by prime factorization is 90.
LCM of 9 and 10 by Listing Multiples
To calculate the LCM of 9 and 10 by listing out the common multiples, we can follow the given below steps:
- Step 1: List a few multiples of 9 (9, 18, 27, 36, 45, 54, 63, . . . ) and 10 (10, 20, 30, 40, . . . . )
- Step 2: The common multiples from the multiples of 9 and 10 are 90, 180, . . .
- Step 3: The smallest common multiple of 9 and 10 is 90.
∴ The least common multiple of 9 and 10 = 90.
LCM of 9 and 10 by Division Method
To calculate the LCM of 9 and 10 by the division method, we will divide the numbers(9, 10) by their prime factors (preferably common). The product of these divisors gives the LCM of 9 and 10.
- Step 1: Find the smallest prime number that is a factor of at least one of the numbers, 9 and 10. Write this prime number(2) on the left of the given numbers(9 and 10), separated as per the ladder arrangement.
- Step 2: If any of the given numbers (9, 10) 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 9 and 10 is the product of all prime numbers on the left, i.e. LCM(9, 10) by division method = 2 × 3 × 3 × 5 = 90.
☛ Also Check:
- LCM of 35 and 60 - 420
- LCM of 72 and 96 - 288
- LCM of 16 and 36 - 144
- LCM of 34 and 51 - 102
- LCM of 12 and 40 - 120
- LCM of 90 and 105 - 630
- LCM of 3 and 3 - 3
LCM of 9 and 10 Examples
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Example 1: The product of two numbers is 90. If their GCD is 1, what is their LCM?
Solution:
Given: GCD = 1
product of numbers = 90
∵ LCM × GCD = product of numbers
⇒ LCM = Product/GCD = 90/1
Therefore, the LCM is 90.
The probable combination for the given case is LCM(9, 10) = 90. -
Example 2: The GCD and LCM of two numbers are 1 and 90 respectively. If one number is 10, find the other number.
Solution:
Let the other number be y.
∵ GCD × LCM = 10 × y
⇒ y = (GCD × LCM)/10
⇒ y = (1 × 90)/10
⇒ y = 9
Therefore, the other number is 9. -
Example 3: Find the smallest number that is divisible by 9 and 10 exactly.
Solution:
The smallest number that is divisible by 9 and 10 exactly is their LCM.
⇒ Multiples of 9 and 10:- Multiples of 9 = 9, 18, 27, 36, 45, 54, 63, 72, 81, 90, . . . .
- Multiples of 10 = 10, 20, 30, 40, 50, 60, 70, 80, 90, . . . .
Therefore, the LCM of 9 and 10 is 90.
FAQs on LCM of 9 and 10
What is the LCM of 9 and 10?
The LCM of 9 and 10 is 90. To find the LCM of 9 and 10, we need to find the multiples of 9 and 10 (multiples of 9 = 9, 18, 27, 36 . . . . 90; multiples of 10 = 10, 20, 30, 40 . . . . 90) and choose the smallest multiple that is exactly divisible by 9 and 10, i.e., 90.
If the LCM of 10 and 9 is 90, Find its GCF.
LCM(10, 9) × GCF(10, 9) = 10 × 9
Since the LCM of 10 and 9 = 90
⇒ 90 × GCF(10, 9) = 90
Therefore, the greatest common factor (GCF) = 90/90 = 1.
What is the Relation Between GCF and LCM of 9, 10?
The following equation can be used to express the relation between GCF and LCM of 9 and 10, i.e. GCF × LCM = 9 × 10.
What is the Least Perfect Square Divisible by 9 and 10?
The least number divisible by 9 and 10 = LCM(9, 10)
LCM of 9 and 10 = 2 × 3 × 3 × 5 [Incomplete pair(s): 2, 5]
⇒ Least perfect square divisible by each 9 and 10 = LCM(9, 10) × 2 × 5 = 900 [Square root of 900 = √900 = ±30]
Therefore, 900 is the required number.
What are the Methods to Find LCM of 9 and 10?
The commonly used methods to find the LCM of 9 and 10 are:
- Division Method
- Listing Multiples
- Prime Factorization Method
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