LCM and HCF

Factor :   Factor for a given number are all the numbers which divides given number completely i.e. if you divide given number by factor then there will be no remainder.

Question Write all the factors of 100 ?
Prime Number : are the numbers which divided completely by only itself or one.

               example 2 , 3 , 5 so on

Question :  Write all the prime number till 100 ?

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HCF : Highest common factor of two or more number is the largest number that divide all the number completely

   Factor of 10 are 1 ,  2  and 5
   Factor of 15 are 1 , 3   and 5
 so common factor of 10 and 15 are 1 and 5 in  which 5 is largest so HCF = 5
Note : HCF will be always less than the smallest number or equal to the smallest number.
           HCF for prime numbers is 1. i.e there is no common factor other than 1.
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 LCM : Least common multiple is the smallest non zero number that is a multiple of two or more numbers.
Question Find LCM of 80 and 30Question Find LCM of 80 and 30

 Factor of 30 :  2 , 3 , 5
Factor of    80 : 2 , 2 , 2 , 2 , 5

 LCM      2 x 5    x   2 x 2 x 2 x 3     =  240
             ! -------!      !---------------!
             common        All other
              Factor            Factor
lcm_hcf_using_prime_factor




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 Important points LCM and HCF which are helpful tricks must remember

 1) Product of Two Numbers = Product of LCM and HCF

 2) LCM of given number is always a multiple of HCF .
                                                           HCF of numerator 
3) HCF of fraction numbers =  ---------------------------------------
                                                           LCM of denominator 

                                                                 LCM of numerator 
4) LCM of fraction numbers = -----------------------------------------
                                                                   HCF of denominator

     

Comments

  1. Unknown11 July 2017 at 09:29

    Nice post on lcm and hcf .pl share some questions on lcm and hcf

    ReplyDelete

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