223 LearnersLast updated on May 26th, 2025
LCM of 5 and 15
LCM is a common multiple, the smallest value between the numbers 5 and 15. Did you know? We apply LCM unknowingly in everyday situations like setting alarms and to synchronize traffic lights and when making music.
How to find the LCM of 5 and 15
The LCM of 5 and 15 is 15. We can find the LCM using the Listing multiples method, the prime factorization method and the long division method. These are explained below.
LCM of 5 and 15 using the Listing Multiples Method
Step 1: Write down the multiples of the numbers. Don’t stop too early.
— Multiples of 5 = 5,10,15,20,25,30,…
— Multiples of 15 = 15,15,45,60,75,…
Step 1: Find the smallest number common between the written multiples of 5, 15.
— The smallest common multiple is 15
Thus, LCM(5,15) = 15
LCM of 5 and 15 using the Prime Factorization Method
Step 1: factorize the numbers into its prime factors
5 = 5×1
15 = 5×3
Step 2: find the highest powers of the factors of 5 and 15
Step 2: Multiply the highest powers
LCM(5,15) = 15
LCM of 5 and 15 using the Division Method
- Write the numbers 5,15 in a row
- Divide them by their common prime factors, if there is one
- Carry forward the numbers that are left undivided by the previously chosen factor
- Continue dividing until the remainder is ‘1’
- Multiply the divisors to find the LCM
- LCM(5,15) = 15
Common Mistakes and how to avoid them while finding the LCM of 5 and 15
Listed here are a few mistakes that one can commit when trying to find the LCM of the numbers 5 and 15. Try to avoid them.
Mistake 1
Listing incorrect multiples
If the LCM of given numbers is 15, double-check that the number appears on the list of both 5 and 15
LCM of 5 and 15, examples
Problem 1
The LCM of two numbers is 15, and one number is 5, what percentage of the LCM is 5?
Percentage = Number/LCM×100
Percentage = 5/15×100=33.33%
Explanation
Thus, 5 is 33.33% of the LCM.
Problem 2
If the LCM of 5 and a number xxx is 15, what is xxx?
The LCM(5, x) = 15. Since the prime factorization of 15 is 31.×51, and the LCM must include both the 3 and the 5,x must be 15.
Explanation
The missing number must contribute the factors that 5 doesn’t have to make the LCM 15.
Problem 3
If the LCM of 5 and 15 is increased by 50%, what is the new value?
LCM(5, 15) = 15.
50% increase = 50/100×15=7.5
New value = 15 + 7.5 = 22.5.
Explanation
A percentage increase involves multiplying the original value by the percentage and adding the result back to the original.
FAQs on LCM of 5 and 15
1.What is the LCM of 5,10 and 15?
2.What are the common factors of 3 and 5?
3.What are the common factors of 5 and 12 ?
4.What is the LCM of 12 and 15?
5.What is the LCM of 5 and 25 ?
6.How can children in Singapore use numbers in everyday life to understand LCM of 5 and 15?
7.What are some fun ways kids in Singapore can practice LCM of 5 and 15 with numbers?
8.What role do numbers and LCM of 5 and 15 play in helping children in Singapore develop problem-solving skills?
9.How can families in Singapore create number-rich environments to improve LCM of 5 and 15 skills?
Important glossaries on the LCM of 5 and 15
- Multiple — product of a number and a natural integer
- Prime factor — number one gets after prime factorization any given number
- Prime factorization — the process of breaking the number into its prime factors.
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About BrightChamps in Singapore
Hiralee Lalitkumar Makwana
About the Author
Hiralee Lalitkumar Makwana has almost two years of teaching experience. She is a number ninja as she loves numbers. Her interest in numbers can be seen in the way she cracks math puzzles and hidden patterns.
Fun Fact
: She loves to read number jokes and games.
