What is the LCM and the HCF of 924 and 126
First find the prime factors of the two numbers:
924 = 2^2*3*7*11
126 = 2*3^2*7
For the HCF use the factors that are common to both: 2*3*7 = 42
For the LCM use the largest factors that appear in either set: 2^2*3^2*7*11 = 2772