# Gcf of 15 18 and 24 relationship

### Greatest Common Factor Calculator

Learn how to find the greatest common factor using factoring, prime factorization and the Euclidean For example, for the set of numbers 18, 30 and 42 the GCF = 6. The factors of are 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 40, 60, We will learn the relationship between H.C.F. and L.C.M. of two numbers. First we need to find the highest common factor (H.C.F.) of 15 and 18 which is 3. The Greatest Common Factor is the largest whole number that divides evenly two or more 42 = 24 · 1 + 18 GCF(42,24) = GCF(24,18). 24 = 18 · 1+6 . Problem George made enough money by selling candy bars at 15 cents each to buy if GCF(a,b) = a? (g) What is the relationship between a and b if LCM(a,b) = a?.

Well we already have 1 three.

And we already have 1 two, so we just need 2 more twos. So 2 times 2. So this makes it-- let me scroll up a little bit-- this right over here makes it divisible by And so this is essentially the prime factorization of the least common multiple of 30 and You take any one of these numbers away, you are no longer going to be divisible by one of these two numbers. If you take a two away, you're not going to be divisible by 24 anymore.

If you take a two or a three away. If you take a three or a five away, you're not going to be divisible by 30 anymore. And so if you were to multiply all these out, this is 2 times 2 times 2 is 8 times 3 is 24 times 5 is Now let's do one more of these.

### Find the LCM and the GCF of Integers - Examples and Questions with Answers (Grade 5)

Umama just bought one package of 21 binders. Let me write that number down. She also bought a package of 30 pencils. She wants to use all of the binders and pencils to create identical sets of office supplies for her classmates.

What is the greatest number of identical sets Umama can make using all the supplies? So the fact that we're talking about greatest is clue that it's probably going to be dealing with greatest common divisors. And it's also dealing with dividing these things. We want to divide these both into the greatest number of identical sets.

So there's a couple of ways we could think about it. Let's think about what the greatest common divisor of both these numbers are. Or I could even say the greatest common factor. The greatest common divisor of 21 and So what's the largest number that divides into both of them? So we could go with the prime factor.

We could list all of their normal factors and see what is the greatest common one. Or we could look at the prime factorization. So let's just do the prime factorization method.

So 21 is the same thing as 3 times 7. These are both prime numbers. We already did it actually just now. And 15 is 3 times 5. So what's the largest number of prime numbers that are common to both factorizations? Well you only have a three right over here. Then you don't have a three times anything else.

**Dr. Phil Tells A 53-Year-Old Why Marrying His 24-Year-Old Fiancée Has A High Risk For Divorce**

So this is just going to be equal to 3. So this is essentially telling us, look, we can divide both of these numbers into 3 and that will give us the largest number of identical sets.

So just to be clear of what we're doing. So we've answered the question is 3, but just to visualize it for this question, let's actually draw 21 binders. So let's say the 21 binders so 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, And then 30 pencils, so I'll just do those in green.

Let me just copy and paste that. This is getting tedious. So copy and paste.

## Relationship between H.C.F. and L.C.M.

So that's 20 and then paste that is Now, we figured out that 3 is the largest number that divides into both of these evenly. So I can divide both of these into groups of 3. So for the binders, I could do it into three groups of 7. And then for the pencils, I could do it into three groups of So if there are three people that are coming into this classroom, I could give them each seven binders and 10 pencils.

But that's the greatest number of identical sets Umama can make. However, GCF 0, 0 is undefined. The most efficient method you use depends on how many numbers you have, how large they are and what you will do with the result.

- GCF & LCM word problems
- Greatest Common Factor GCF Calculator

Factoring To find the GCF by factoring, list out all of the factors of each number or find them with a Factors Calculator. The whole number factors are numbers that divide evenly into the number with zero remainder. Given the list of common factors for each number, the GCF is the largest number common to each list.

## Find the LCM and the GCF of Integers - Examples and Questions with Answers (Grade 5)

Find the GCF of 18 and 27 The factors of 18 are 1, 2, 3, 6, 9, The factors of 27 are 1, 3, 9, The common factors of 18 and 27 are 1, 3 and 9. The greatest common factor of 18 and 27 is 9. Find the GCF of 20, 50 and The factors of 20 are 1, 2, 4, 5, 10, The factors of 50 are 1, 2, 5, 10, 25, The factors of are 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 40, 60, The common factors of 20, 50 and are 1, 2, 5 and Include only the factors common to all three numbers.

The greatest common factor of 20, 50 and is Prime Factorization To find the GCF by prime factorization, list out all of the prime factors of each number or find them with a Prime Factors Calculator.

List the prime factors that are common to each of the original numbers.