Question

3
Find the HCF of the following numbers by prime factorisation.
a 12.16 b 54, 72
c 30.96 d 128, 32 e 240,135 f 85, 136 g 242,88 h 333, 18
Find the HCF of the following groups of numbers using the method of division by common factors.
a 12, 18, 24
b 28, 35, 49
c 32, 64, 96, 128 d 70, 105, 175
e 24, 45, 63
f 84, 96, 120
g 325, 525
h 64.96, 144
3 Find the HCF of the following groups of numbers using the long division method.
a 144, 198
b 234, 572
c 144, 180, 384 d 45, 60, 330
e 70, 140, 420
f 184.230.276 g 136, 170, 255 h 1624, 1276, 522​

Answer 1

Step-by-step explanation:

Prime factorisation of the given numbers are :

54=2×3×3×3

72=2×2×2×3×3

90=2×3×3×5

Notice that 2 occurs as a common prime factor at least one times and 3 at least two times in given numbers.

∴ H.C.F =2×3×3=18