Question

Find the HCF of the following numbers:
18, 54, 81

Answer 1

HCF of two or more number is the highest number which divides the given numbers exactly.
Factors of 18 = $2\times 3\times 3$
Factors of 54 = $2\times 3\times 3\times 3$
Factors of 81 = $3\times 3\times 3\times 3$
HCF of 18, 54, and 81 = $3\times 3=9$