GCF of 5 and 8
GCF of 5 and 8 is the largest possible number that divides 5 and 8 exactly without any remainder. The factors of 5 and 8 are 1, 5 and 1, 2, 4, 8 respectively. There are 3 commonly used methods to find the GCF of 5 and 8  Euclidean algorithm, long division, and prime factorization.
1.  GCF of 5 and 8 
2.  List of Methods 
3.  Solved Examples 
4.  FAQs 
What is GCF of 5 and 8?
Answer: GCF of 5 and 8 is 1.
Explanation:
The GCF of two nonzero integers, x(5) and y(8), is the greatest positive integer m(1) that divides both x(5) and y(8) without any remainder.
Methods to Find GCF of 5 and 8
Let's look at the different methods for finding the GCF of 5 and 8.
 Listing Common Factors
 Using Euclid's Algorithm
 Long Division Method
GCF of 5 and 8 by Listing Common Factors
 Factors of 5: 1, 5
 Factors of 8: 1, 2, 4, 8
Since, 1 is the only common factor between 5 and 8. The Greatest Common Factor of 5 and 8 is 1.
GCF of 5 and 8 by Euclidean Algorithm
As per the Euclidean Algorithm, GCF(X, Y) = GCF(Y, X mod Y)
where X > Y and mod is the modulo operator.
Here X = 8 and Y = 5
 GCF(8, 5) = GCF(5, 8 mod 5) = GCF(5, 3)
 GCF(5, 3) = GCF(3, 5 mod 3) = GCF(3, 2)
 GCF(3, 2) = GCF(2, 3 mod 2) = GCF(2, 1)
 GCF(2, 1) = 1 (∵ GCF(X, 1) = 1)
Therefore, the value of GCF of 5 and 8 is 1.
GCF of 5 and 8 by Long Division
GCF of 5 and 8 is the divisor that we get when the remainder becomes 0 after doing long division repeatedly.
 Step 1: Divide 8 (larger number) by 5 (smaller number).
 Step 2: Since the remainder ≠ 0, we will divide the divisor of step 1 (5) by the remainder (3).
 Step 3: Repeat this process until the remainder = 0.
The corresponding divisor (1) is the GCF of 5 and 8.
☛ Also Check:
 GCF of 18 and 81 = 9
 GCF of 16 and 28 = 4
 GCF of 108 and 24 = 12
 GCF of 21 and 36 = 3
 GCF of 35 and 49 = 7
 GCF of 20 and 100 = 20
 GCF of 8 and 9 = 1
GCF of 5 and 8 Examples

Example 1: For two numbers, GCF = 1 and LCM = 40. If one number is 8, find the other number.
Solution:
Given: GCF (z, 8) = 1 and LCM (z, 8) = 40
∵ GCF × LCM = 8 × (z)
⇒ z = (GCF × LCM)/8
⇒ z = (1 × 40)/8
⇒ z = 5
Therefore, the other number is 5. 
Example 2: Find the GCF of 5 and 8, if their LCM is 40.
Solution:
∵ LCM × GCF = 5 × 8
⇒ GCF(5, 8) = (5 × 8)/40 = 1
Therefore, the greatest common factor of 5 and 8 is 1. 
Example 3: Find the greatest number that divides 5 and 8 exactly.
Solution:
The greatest number that divides 5 and 8 exactly is their greatest common factor, i.e. GCF of 5 and 8.
⇒ Factors of 5 and 8: Factors of 5 = 1, 5
 Factors of 8 = 1, 2, 4, 8
Therefore, the GCF of 5 and 8 is 1.
FAQs on GCF of 5 and 8
What is the GCF of 5 and 8?
The GCF of 5 and 8 is 1. To calculate the greatest common factor (GCF) of 5 and 8, we need to factor each number (factors of 5 = 1, 5; factors of 8 = 1, 2, 4, 8) and choose the greatest factor that exactly divides both 5 and 8, i.e., 1.
What is the Relation Between LCM and GCF of 5, 8?
The following equation can be used to express the relation between LCM and GCF of 5 and 8, i.e. GCF × LCM = 5 × 8.
If the GCF of 8 and 5 is 1, Find its LCM.
GCF(8, 5) × LCM(8, 5) = 8 × 5
Since the GCF of 8 and 5 = 1
⇒ 1 × LCM(8, 5) = 40
Therefore, LCM = 40
☛ GCF Calculator
How to Find the GCF of 5 and 8 by Prime Factorization?
To find the GCF of 5 and 8, we will find the prime factorization of the given numbers, i.e. 5 = 5; 8 = 2 × 2 × 2.
⇒ There is no common prime factor for 5 and 8. Hence, GCF (5, 8) = 1.
☛ Prime Number
How to Find the GCF of 5 and 8 by Long Division Method?
To find the GCF of 5, 8 using long division method, 8 is divided by 5. The corresponding divisor (1) when remainder equals 0 is taken as GCF.
What are the Methods to Find GCF of 5 and 8?
There are three commonly used methods to find the GCF of 5 and 8.
 By Prime Factorization
 By Long Division
 By Euclidean Algorithm
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