Question

find the HCF of 21,42,56​

Answer 1

Prime factorization of 21 :

$\to$ 21 = 3 × 7

Prime factorization of 42 :

$\to$ 2 × 3 × 7

Prime factorization of 56 :

$\to$ 56 = 2 × 2 × 2 × 7

$\therefore \:$ HCF = 7

Answer 2

Answer:

The HCF of 21, 42, and 56​ will be 7.

Step-by-step explanation:

Given: the numbers are 21, 42, and 56.

We have to find the HCF of the above numbers.

• For this, we will first find the factors of the above numbers.
• And then, the largest positive integer that divides each of the given integers will be the HCF of the above numbers.

We are solving in the following way:

We have,

The numbers are 21, 42, and 56.

The factors of the above numbers will be:

The factors of 21 are: $1, 3, 7, 21$

The factors of 42 are: $1, 2, 3, 6, 7, 14, 21, 42$

The factors of 56 are: $1, 2, 4, 7, 8, 14, 28, 56$

From the above, we can see that 7 is the largest positive integer that divides each of the above integers

So, the greatest common factor(HCF) is 7.