Question

find the HCF of the following numbers using the prime factorization method. (a)64and320 (b)81and72​

Answer 1

To Find:

HCF of the following numbers using the prime factorisation method.

• a) 64 and 320
• b) 81 and 72

Finding HCF using prime factorisation:

a) 64 and 320

• Factors of 64 = 2 × 2 × 2 × 2 × 2 × 2
• Factors of 320 = 2 × 2 × 2 × 2 × 2 × 2 × 5

HCF (64, 320) = 2 × 2 × 2 × 2 × 2 × 2 = 64

Hence,

• HCF of 64 and 320 is 64.

b) 81 and 72

• Factors of 81 = 3 × 3 × 3 × 3
• Factors of 72 = 2 × 2 × 2 × 3 × 3

HCF (81, 72) = 3 × 3 = 9

Hence,

• HCF of 81 and 72 is 9.

Answer 2

Step-by-step explanation:

(a) Prime Factorization of 64= 2×2×2×2×2×2

Prime Factorization of 320=2×2×2×2×2×2×5

Here, 2×2×2×2×2×2 are common in both so The HCF= 2×2×2×2×2×2=64

(b) Prime Factorization of 81=3×3×3×3

Prime Factorization of 72=2×2×2×3×3

Here, 3×3 are common in both so the HCF=3×3=9