Question

Using prime factorisation, find the HCF of 144, 180 and 192.

Answer 1

HCF (144, 180, 192)

Prime factorisation of 144, 180, 192.

2	144
2	72
2	36
2	18
3	9
3	3
	1

2⁴ × 3²

2	180
2	90
3	45
3	15
5	5
	1

2² × 3² × 5

2	192
2	96
2	48
2	24
2	12
2	6
3	3
	1

2⁶ × 3¹

The common factors are 2² × 3 = 12

HCF (144, 180, 192) = 12