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LCM for 12, 16 and 30 please help?

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LCM for 12, 16 and 30 please help?

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  1. The LCM for 12, 16 and 30 is the lowest number that'll go into them all evenly, which is 2.


  2. 2.

  3. idk!

  4. the least common multiple would be 2.

  5. start by setting up multiples and seeing which number is a multiple of all those numbers:

    12-

    2, 6

    3, 4

    16-

    2, 8

    4, 4

    30-

    2, 15

    3, 10

    5, 6

    now which number is the lowest that they all share?

  6. 240

    12x20=240

    16x15=240

    30x8=240

  7. the lcm is 2


  8. I'm not sure this question needs another answer but here goes.  This process can be applied to any group of numbers.

    We have a theorem that says that for any integers a and b:

    lcm(a,b) = (ab)/gcd(a,b)

    Where we obtain the gcd(a,b) by the Euclidean Algorithm.

    The lcm(12,16,30) is equivalent to lcm(lcm(12,16),30).

    Thus we first compute lcm(12,16):

    By our theorem lcm(12,16) = (12)(16)/gcd(12,16)

    By the Eucldiean Algorithm gcd(12,16) = 4 , since

    16 = 1*12 + 4

    12 = 3*4 + 0

    Thus lcm(12,16) = (12)(16)/(4) = 48

    Now we compute lcm(48,30)

    lcm(48,30) = (48)(30)/gcd(48,30)

    By the Euclidean algorithm gcd(48,30) = 6 , since

    48 = 1*30 + 18

    30 = 1*18 + 12

    18 = 1*12 + 6

    12 = 2*6 + 0

    Thus lcm(12,16,30) = lcm(48,30) = (48)(30)/(6) = 240

  9. To find LCM and GCD, use the prime factors:

    12 = 2*2*3

    16 = 2*2*2*2

    30 = 2*3*5

    The smallest number that can be divided by all of them must contain as many primes as each one:

    We need four 2's (this covers all of them, including the 16), we need one three (to cover the 12 and 30) and we need one five:

    2*2*2*2*3*5 = 240

    No smaller number can do, because any smaller number would be missing one fo the required factors.

    To find the biggest number that can divide all three, we can only take factors that are common to all of them:

    That is 2.

    We cannot take a 3 (no 3 in 16) and we cannot take a 5 (no 5 in 12).  We cannot take another 2 (there is only one 2 in 30)

  10. 12 = 2*2*3

    16 = 2*2*2*2

    30 = 2*3*5

    The LCM will then need 4 2's, one 3 and one 5

    2*2*2*2*3*5 = 240

  11. beats me!

  12. 2

  13. 2, I think.  Ive been out of school for over ten years.

  14. To find the LCM, start by factoring each number:

    12 = 2*2*3

    16 = 2*2*2*2

    30 = 2*3*5

    Then, for each factor, see where it appears the most.  For example, 2 appears twice in the factors for 12, four times in the factors of 16, and once in the factors for 30.  Then multiply each factor together the highest number of times that it appears.

    2*2*2*2*3*5 = 240

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