Solution:
Concept- In order to get the LCM and HCF we must first know their factors.We can get the factors by prime factorisation method.
With prime factorisation we can get the prime factors of that number.
Factors of 861:
Factors of 1353:
HCF of 861 and 1353 is:The common factors of both are 3 and 41.
LCM of 861 and 1353 is:
Hence, the correct answer is option 2.
