Question

Find the LCM of 120,180 and 280 using prime factorisation method.​

Answer 1

Given:

LCM of 120,180 and 280 using prime factorization method.​

(1) 120

2   120  

2   60

2  30

3   15

5   5

    1

120=2×2×2×3×5

     =2³×3×5

(2) 180

2   180

2   90

3  45

3   15

5    5

    1

180=2×2×3×3×5

  =2²×3²×5

(3)  280

2    280

2   140

2   70

5   35

7     7

    1

280=2×2×2×5×7

  =2³×5×7

LCM of 120,180 and 280=2³×3²×5×7

                                       =2520

Hence the LCM of 120,180 and 280 using prime factorization method. is 2520

Answer 2

Given:

120,180 and 280 using the prime factorization method.​

Find:

Find the LCM

Solution:

(1) 120

2  120  

2  60

2  30

3   15

5   5

   1

$120=2*2*2*3*5$

$=2^{3}*3*5$

 (2) 180

2   180

2   90

3  45

3   15

5    5

   1

$180=2*2*3*3*5$

$=2^{2} *3^{2} *5$

(3)  280

2    280

2   140

2   70

5   35

7     7

    1

$280=2*2*2*5*7$

 $=2^{3} *5*7$

LCM of   $120,180$  and  $280=2^{3}*3^{2} *5*7$

$=2520$

Hence, we get the LCM of  $120,180$  and $280$ using prime factorization method is $2520$