Find the HCF of the following numbers: (a) 24, 180; (b) 42, 75, 24: Class 7

Find the HCF of the following numbers: (a) 24, 180; (b) 42, 75, 24: Class 7

Question 1.

Find the HCF of the following numbers: Class 7

(a) 24, 180

Solution:

So, HCF = 2 × 2 × 3 = 12.

(b) 42, 75, 24

Solution:

So, HCF = 3.

(c) 240, 378

Solution:

So, HCF = 2 × 3 = 6.

(d) 400, 2500

Solution:

So, HCF = 2 × 2 × 5 × 5 = 100

(e) 300, 800

Solution:

So, HCF = 2 × 2 × 5 × 5 = 100

Question 2.

Consider the numbers 72 and 144. Suppose they are factorised into composite numbers as : 72 = 6 × 12 and 144 = 8 × 18. Seeing this, can one say that these two numbers have no common factor other than 1? Why not? Class 7

Solution:

We cannot, because the factorisations 6 × 12 and 8 × 18 are not in the prime factorisation forms. The prime factorisation forms may have common factors.