# What is the HCF of 40, 42, and 45?

HCF (Highest Common Factor) of two numbers is the largest possible number which divides the two numbers exactly without leaving any remainder.

## Answer: HCF of 40, 42, and 45 is 1

HCF of 40, 42, and 45 is the highest number that divides 40, 42, and 45 exactly leaving the remainder 0.

## Explanation:

We will show two methods to find the highest common factor of 40, 42 and 45

We can find the HCF by the following methods

- HCF of 40, 42, and 45 by Listing the Common Factors
- HCF of 40, 42, and 45 by Prime Factorization

### Method 1: HCF of 40, 42, and 45 by Listing the Common Factors

The factors of 40, 42, and 45 are given below.

Here, the common factor among the factors of 40, 42, and 45 is 1.

So, the highest common factor of 40, 42, and 45 is 1.

### Method 2: HCF of 40, 42, and 45 by Prime Factorization

Let us represent 40, 42, and 45 as a product of its prime factors.

Prime factorization of 40 = 2 × 2 × 2 × 5

Prime factorization of 42 = 2 × 3 × 7

Prime factorization of 45 = 3 × 3 × 5

Observe that there's no common factor in the prime factorization of 40, 42, and 45.

So, HCF of 40, 42, and 45 is 1.

The solution of HCF of 40, 42, and 45 is the same as any of the above methods.