Explain the HCF and LCM of numbers.

A factor is a number that divides into another number exactly and without leaving a remainder. 

Factors of 12 = 1, 2, 3, 4, 6, 12

A prime number has only two factors - the number itself and 1.

Prime factors of 12

12 = 2 x 2 x 3

HCF or highest common factor of two or more numbers is the greatest common factor present in those two or more numbers

Example: HCF of 15 and 25 is 5

LCM or lowest common multiple of two or more numbers is the least number that is divisible by those two or more numbers

Example: 

LCM of 6, 15, 24 is 120