Question

13. Find the HCF of the following by prime factorisation method:
(a) 18 and 45
(b) 240 and 300
(c) 72 and126​

Answer 1

Step-by-step explanation:

hcf of 18 and 45

18=9×2

45=9×5

hcf of 1i and 45 is 9

hcf of 240 and 300

240=60×4

300=60×5

hcf of 240,300=60

hcf of 72 and 126

72=18×4

126=18×7

hcf of 72 and 126 is 18

Answer 2

Answer:

i) 18= 2×3×3

45= 3×3×5

So, HCF = 3

ii) 240= 2×2×2×2×3×5

300 = 2×2×3×5×5

So, HCF = 2×2×3×5

= 60

iii) 72 = 2× 2×2×3×3

126= 2×3×3×7

So, HCF = 2×3

=6.