Free Study Material For RRB Examination: Mathematics (HCF & LCM)
Free Study Material For RRB Examination
Subject : Mathematics (HCF & LCM)
Highest Common Factor
The highest common factor of two or more given numbers is the largest of their common factors. It is known as GCD also.
eg, Factors of 20 are 1, 2, 4, 5, 10, 20
Factors of 36 are 1, 2, 3, 4, 6, 9, 12, 18, 36
Here greatest and common factor of 20 and 36 is 4.
:. HCF of 20 and 36 is 4.
Least Common Multiple
The least common multiple of two or more given numbers is the least of their common multiples.
eg, Multiple of 25 are 25, 50, 75, 100, 125, 150, 175, ....
Multiple of 30 are 30, 60, 90, 120, 150, 180, 210, ....
Here 150 is least common multiple of 25 and 30
:. LCM of 25 and 30 is 150.
Using Division Method
Example 1: Determine the HCF and LCM of 36, 48, 64 and 72.
Solution. To find HCF