Question

find the lcm and hcf of the following integer. a)12,15,21 (b) 8,9 and 25​

Answer 1

Answer:

a) 12 , 15 and 21

Prime factors of :

1) 12 = 2×2×3

2^2 × 3

2) 15 = 3×5

3) 21 = 3×7

LCM ( 12 , 15 , 21 ) = 2^2 × 3 × 5 × 7

= 420

HCF ( 12 , 15 , 21 ) = 3

b) 8 , 9 and 25

Prime factors of :

1) 8 = 2×2×2

= 2^3

2) 9 = 3×3

= 3^2

3) 25 = 5×5

= 5^2

LCM ( 8 , 9 , 25 ) = 2^3×3^2×5^2

= 1800

HCF ( 8 , 9 , 25 ) = 1

Answer 2

:

Mark Me As Brainliest And Thank Me If The Answer Is Useful.

-- :

Using prime factorisation method:

(i) 12, 15 and 21

Factor of 12=2×2×3

Factor of 15=3×5

Factor of 21=3×7

HCF (12,15,21)=3

LCM (12,15,21)=2×2×3×5×7=420

(ii) 17, 23 and 29

Factor of 17=1×17

Factor of 23=1×23

Factor of 29=1×29

HCF (17,23,29)=1

LCM (17,23,29)=1×17×23×29=11,339

(iii) 8, 9 and 25

Factor of 8=2×2×2×1

Factor of 9=3×3×1

Factor of 25=5×5×1

HCF (8,9,25)=1

LCM (8,9,25)=2×2×2×3×3×5×5=1,800