Sir I still dont undestood how to find LCM.Please show me with an example
LCM of 120 and 144 = 2 × 2 × 2 × 2 × 3 × 3 × 5 = 720.
720 is the smallest number which is divisible by both 120 and 144.
Similarly, consider two numbers 24 and 36 whose LCM is to be find out.
In order to find out LCM, firstly we write the prime factors of given number as:
24 = 2 × 2 × 2 × 3
and 36 = 2 × 2 × 3 × 3
Now, we check the prime factors of two numbers.
The prime factor or digit which is repeating in both the numbers is written once and the digit which is occuring once in any number has to be written as such. All the written digits must be enclosed in multiplication and the multiplication of these digits will give the LCM of two numbers.
Here, in number 24 we have two 2's and one 3 whereas in number 36 we have two 2's and two 3's.
So, the LCM of 24 and 36 will have two 2's (which are common in both 24 and 36), one 2's from 24 which is uncommon, one 3's which is common in both 24 and 36 and finally the remaining 3 in 36. Now, all these digits are enclosed under multiplication.
Therefore, LCM of 24 and 36 = 2 × 2 × 2 × 3 × 3 = 72
Hope you get it!!