The GCF of 15 and 21 is the largest possible number which exactly divides 15 and 21 without any remainder. The factors of 15 and 21 are **1, 3, 5, 15 and 1, 3, 7, 21** respectively. There are 21 commonly used methods for finding the GCF of 3 and 15 – long division, Euclidean algorithm, and prime factorization.

Also, which list has only the factors of 21?

**The factors of** RSI 21 are 1, 3, 7 and . are **21** .

Here, what is the GCF of 15 and 20?

Answer: The GCF of 15 and 20 is **5** .

Also to know what is the GCF of 7 and 15? What is the GCF of 7 and 15? The GCF of 7 and 15 is **1** .

3 What is the GCF of 15 and 21?

Final Step: Greatest Common Factor Number

We get the factors and prime factors of 15 and 21. The greatest common factor number is the GCF number. So the greatest common factors 15 and 21 are **3** .

**Which 3 numbers make 21?**

**3 + 8 + 10** =21. 3+9+9=21.

**Is 3 a factor of 21 or not?**

Factors **3, 7, 21** of 21:1 .

**Which is the smallest whole number?**

The smallest whole number is ” **0** “(zero).

**What is the GCF of 10 15 and 20?**

As you can see when you list the factors of each number, **5** is the largest number that 10, 15 and 20 divide.

**What is the HCF of 12 and 15?**

HCF of 12 and 15 by prime factorization

The prime factors of 12 and 15 are (2 × 2 × 3) and (3 × 5) respectively. As seen, 12 and 15 have only one common prime factor, that is, **3** . Hence, HCF of 12 and 15 is 3.

**What is the HCF of 15 and 30?**

GCF of 15 and 30 by listing common factors

15 and 30 have 4 common factors, which are 1, 3, 5 and 15. Therefore, the greatest common factor of 15 and 30 is **15** .

**What do 15 and 7 both go in?**

The greatest common factor (GCF) of 7 and 15 is **1** .

**What is the GCF of 7/15 and 21?**

What is the GCF of 7, 15 and 21? Answer: The GCF of 7, 15 and 21 is **1** .

**What is the GCF of 12 and 15?**

Answer: The GCF of 12 and 15 is **3** .

**What is the GCF of 35 and 15?**

Answer: The GCF of 15 and 35 is **5** .

**What is the GCF of 15 and 18?**

Answer: GCF of 15 and 18 is **3** .

**What is the HCF of 16 and 24?**

The HCF of 16 and 24 is **8** . To calculate the Highest Common Factor (HCF) of 16 and 24, we need to factor each number (16 = 1, 2, 4, 8, 16; 24 = 1, 2, 3, 4, 6, Factors of 8) , 12, 24) and choose the highest factor that exactly divides both 16 and 24, that is, 8.

**Which three numbers add to 15?**

- 3X + 3 = 15. 3X + 3 – 3 = 15 – 3.
- 3X = 12. 3X/3 = 12/3.
- X = 4. Which means first number is 4, second number is 4 + 1 and third number is 4 + 2. Therefore, three consecutive integers whose sum is 15 are 4, 5 and 6. 4 + 5 + 6 = 15.

**Which 4 numbers make 15?**

15 is a composite number. 15 = 1 x 15 or 3 x 5. Factors of 15: **1, 3, 5, 15** .

**Which 3 numbers make 15?**

Hence the average sum of three numbers is **45** :3=15. The number 15 is said to be the magic number of the 3×3 square. If you add the middle number 15 three times you can also get 5. Odd numbers 1,3,7, and 9 are cut twice, even numbers 2,4,6,8 appear thrice and number 5 once.

**Which is the smallest factor of 16?**

Factors of 16: **1, 2, 4, 8, 16** . Prime factorization: 16 = 2 x 2 x 2 x 2, which can also be written as 16 = 2⁴. Since 16 = 4, a whole number, 16 is a perfect square.

**What is the HCF of 21 and 29?**

The HCF of 21 and 29 is **1** .

**What is a common factor of 21?**

Factors of 21 = **1, 3, 7 and 21** . Therefore, common factors of 14 and 21 = 1 and 7

**Which is the largest whole number?**

What are whole numbers?

- There is no ‘greatest’ whole number.
- Except 0, every whole number has an immediate predecessor or a number that comes first.
- A decimal number or fraction is between two whole numbers, but whole numbers are not.

**Which number is the smallest or smallest?**

However, we call **the lowest number** “some” for something that is countable, such as people, tourists, oranges, etc. Or the lowest number of “some” if it is a “some” number, such as 3, 65, 8648. We say something at least in quantity, for example the least amount, where money is uncountable.

**Which is the smallest factor of 15?**

So, **1** is the smallest factor of 15.