Guys can somebody explain me the concept of GCF i just started using manhattan gmat book it's the first topic in it.I did understood LCM but GCF is going way over my head
this video is helpful https://www.youtube.com/watch?v=J7K1BLaSX20
basically GCF is like LCM but you only take the prime factors that repeat
so GCF of 45 and 81
45= 3* 3 * 5
81 = 3 * 3* 3 *3
only 3 and a 3 repeat here, so GCF = 3 *3 = 9
















