Question

8. Find the HCF of:
(a) 9 and 12
(b) 15 and 25
(f) 54 and 81
(e) 45 and 75​

Answer 1

Answer:

(a) 9 and 12 HCF is- 3

(b) 15 and 25 HCF is-5

(f) 54 and 81 HCF is - 27

(e) 45 and 75 HCF is - 15

Answer 2

Answer:

 a) Let us represent 9 and 12 as a product of their prime factors:

Prime factorization of 9 is 3 × 3  

Prime factorization of 12 is 2 × 2 × 3

b) Prime factors of 15 = 3×5

Prime factors of 25 = 5×5

H.C.F. → 5

c) 54 = 2×3×3×3

81 = 3x3x3x3

HCF = 3×3×3

HCF = 27

d) Prime factorization of 45 is 3 × 3 × 5

Prime factorization of 75 is 3 × 5 × 5

Common factors = 3, 5

GCF is the product of the factors that are common to each of the given numbers.

GCF = 3 × 5 = 15