What is the HCF of 30 and 42?
The Highest Common Factor of two or more numbers is the largest possible number which divides the given numbers exactly without leaving any remainder or leaving 0 as the remainder.
Answer: HCF (30,42) is 6
Let us see how to find the HCF of 30 and 42
Methods to Find HCF of 30 and 42
Two methods to find the HCF of 30 and 42 are explained below.

HCF of 30 and 42 by Prime Factorization
 HCF of 30 and 42 by Listing the Common Factors
Method1: HCF (30,42): Listing the Common Factors
Factors of 30 : 1, 2, 3, 5, 6, 10, 15 and 30
Factors of 42 : 1, 2, 3, 6, 7, 14, 21 and 42
Common Factors (30,42): 1, 2, 3 and 6
HCF (30,42) is 6
Method2: HCF (30,42): Long Division

Step 1: Divide the larger number 42 by the smaller number 30 and find the remainder.

Step 2:Now make the remainder of the above step as the divisor and the divisor of the above step as the dividend and perform the same long division again.

Step 3: Continue till remainder is obtained as 0
HCF can be found by making use of any the above methods but the answer will remain the same.