Question

what is the highest common factor of 54, 72, 90

Answer 1

Given:

Numbers are 54, 72 and 90.

To Find:

Find HCF of 54, 72 and 90 by prime factorisation method.

Solution:

Prime factorization of given number are:

54 = 2 ×3 ×3 ×3

72 = 2 ×2 ×2 ×3 ×3

90 = 2 ×3 ×3 ×5

We know that the highest common factor is the multiplication of all common factor of prime factorization of all number, So:

H.C.F = 2 ×3 ×3 =18

So HCF of 54, 72 and 90 by prime factorisation method is 18.

Answer 2

Step-by-step explanation:

54 = { 1, 2, 3, 6, 9, 18, 27, 54}

72 = {1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 39, 72}

90 = {1, 2, 3, 5, 9, 10, 18, 30, 45, 90}

So the common factor is {1, 2, 3, 18}

If you see my Ans pleas like