Answer:

2

Step-by-step explanation:

18 = 2*3*3

64 = 2*2*2*2*2

80 = 2*2*2*2*5

Since only 2 is common.

HCF = 2

Answer:

2

Step-by-step explanation:

18=2*3*3

64=2*2*2*2*2

80=2*2*2*2*5

2 is common in all

therefore=

HCF=2