Question

Explain how to find a LCM with simple example​

Answer 1

Answer:

suppose you have to find the LCM of 20 and 40

20=2×2×5

40=2×2×2×5

LCM=2³×5=40

Answer 2

Answer:

Least Common Multiple(LCM) is a method to find the smallest common multiple between any two or more numbers.

Let us take multiples of 4 and 6 ,

4 : 4,8,12,16,20,24,28,…..

6: 6,12,18,24,30,36,42…..

From the above two expressions we can see, 4 and 6 have common multiples as 12 and 24. They may have more common multiple if we go beyond. Now, the smallest or least common multiple for 4 and 6 is 12. Therefore, 12 is the LCM of 4 and 6.

Another method to find the LCM of the given numbers is prime factorization. Suppose, there are three numbers 12, 16 and 24. Let us write the prime factors of all three numbers individually.

12 = 2 x 2 x 3

16 = 2 x 2 x 2 x 2

Now writing the prime factors of all the three numbers together, we get;

12 x 16 = 2 x 2 x 3 x 2 x 2 x 2 x 2  

Now pairing the common prime factors we get the LCM. So the LCM of 12, 16 will be;

LCM (12, 16) = 2 x 2 = 4