Find the least common multiple of 7.2, 1.08 and 21

Post a reply

Smilies
:D :) :( :o :shock: :? 8) :lol: :x :P :oops: :cry: :evil: :twisted: :roll: :wink: :!: :?: :idea: :arrow: :| :mrgreen:
BBCode is ON
[img] is ON
[flash] is OFF
[url] is ON
Smilies are ON
Topic review
LaTeX Help
Every formula have to stat with [tex]\textrm{[tex]}[/tex] and ends with [tex]\textrm{[/tex]}[/tex].

   
   

If you wish to attach one or more files enter the details below.

Expand view Topic review: Find the least common multiple of 7.2, 1.08 and 21

Re: Find the least common multiple of 7.2, 1.08 and 21

Post by Angus53 » Sat Feb 10, 2024 10:45 am

To find the least common multiple (LCM) of 7.2, 1.08, and 21, first, express them as integers by multiplying each number by 100 (to remove decimals):

7.2 * 100 = 720
1.08 * 100 = 108

Now, we have 720, 108, and 21.

The prime factorization of these numbers are:
720 = 2^4 * 3^2 * 5
108 = 2^2 * 3^3
21 = 3 * 7

Now, identify the highest power of each prime factor:
- 2^4
- 3^3
- 5
- 7

Now, multiply these highest powers together to find the LCM:
LCM = 2^4 * 3^3 * 5 * 7 = 16 * 27 * 5 * 7 = 8,640

So, the least common multiple of 7.2, 1.08, and 21 is 8,640.

Re: Find the least common multiple of 7.2, 1.08 and 21

Post by Guest » Fri Nov 25, 2022 1:07 am

Finding the Least Common Multiple is not hard. Lcm can be calculated by more than two integers or fractions. And there are several methods you can use. For example Long Division Method, Brute Force Method, Prime Factorization Method. I hope this helps somewhere

Re: Find the least common multiple of 7.2, 1.08 and 21

Post by Guest » Sat Apr 03, 2021 3:34 am

Hey! I used an https://www.meracalculator.com/math/lcm.php by Meracalculater.com and it shows me steps here. PS it removes the decimal and you can understand through the steps.
It shows the LCM is "1512"

Re: Find the least common multiple of 7.2, 1.08 and 21

Post by Guest » Fri Dec 11, 2020 11:08 am

Frankly, I don't know how this has gone on so long. "Least Common Multiple" is usually defined for positive integers because if we allow fractions ANY number is a multiple of any other!

Re: Find the least common multiple of 7.2, 1.08 and 21

Post by Guest » Sat Mar 19, 2016 7:42 pm

Lowest common multiple satisfies the property
Lcm(ab,ac) = a Lcm(b,c)
which implies Lcm(ab,ac,ad) = a Lcm(b,c,d)

So Lcm(7.2,1.08,21) = Lcm(720,108,2100)/100 = 75600/100 = 756

Alternatively (and equivalently) look at the prime factorization (allowing for negative exponents) and take the maximum exponent for each prime
[tex]7.2 = 72/10 = 2^2\times 3^2\times 5^{-1}[/tex]
[tex]1.08 = 108/100 = 3^3\times 5^{-2}[/tex]
[tex]21 = 3^1\times 7^1[/tex] (note that the exponent of 5 is 0)
Lcm has the maximum exponent for each prime factor = [tex]2^2\times 3^3\times 5^0 \times 7^1\times 11^0\times 13^0\times\ldots = 756[/tex].

Hope this helped,

R. Baber.

Re: Find the least common multiple of 7.2, 1.08 and 21

Post by Guest » Sat Mar 19, 2016 3:25 pm

163.296 is the multiplication of the numbers given

Re: Find the least common multiple of 7.2, 1.08 and 21

Post by leesajohnson » Fri Mar 18, 2016 3:12 am

It's 756 the multiplication all the numbers were given.

Re: Find the least common multiple of 7.2, 1.08 and 21

Post by Guest » Sat Sep 20, 2014 6:18 pm

Doing it out again....this time in full with prime factors...then I will hopefully not have any duplicates
I think duplicate 2 in last post...

Find the least common multiple of 7.2, 1.08 and 21
Multiply all by 100 first.

720 = 2^4 x 3^2 x 5

108 = 2^2 x 3^3

2100 = 2^2 x 5^2 x 3 x 7

LCM x100 = 2^4 x 3^3 x 5^2 x 7 = 16 x 27 x 25 x 7 = 75600

So...Real LCM = 756 .......as I had got in an earlier post.......

Check........
7.2 x 105 = 756
1.08 x 700 = 756
21 x 36 = 756
.... so as can be seen .... 756 is a multiple of all the numbers given...........

Re: Find the least common multiple of 7.2, 1.08 and 21

Post by Guest » Sat Sep 20, 2014 4:32 am

Find the least common multiple of 7.2, 1.08 and 21
Multiply all by 100 first.

720 = 6, 6, 5, 4

108 = 6, 6, 3

21 = 3 x 7................should this be mult by 100 ??

2100 = 6 x 7 x 5 x 2 x 5

LCM x 100 = 6 x 6 x 5 x 4 x 3 x 7 x 2 x 5 = 151200
Then real LCM = 1512

which is twice I got in an earlier post....so not least C M ...???

Re: Find the least common multiple of 7.2, 1.08 and 21

Post by Guest » Fri Sep 19, 2014 8:05 pm

Find the least common multiple of 7.2, 1.08 and 21
Multiply all by 100 first.

720 = 6, 6, 5, 4

108 = 6, 6, 3

210 = 6, 5, 7

LCM x 100 = 6 x 6 x 5 x 4 x 3 x 7 = 15120
Then real LCM = 151.2

How is that for an answer........






There is an error in the calcs in the last post.....

=(0.6,0.9,7) /3
=0.2,0.3,7

should be....

=(0.6,0.09,7) /3
=0.2,0.03,7

But wouldn't get my answer anyway.....would now give 1.512 ??

Re: Find the least common multiple of 7.2, 1.08 and 21

Post by TutorSOS » Fri Sep 19, 2014 5:43 pm

(7.2,1.08,21) /2 =(3.6,0.54,21) /2
=(1.8,0.27,21) /3
=(0.6,0.9,7) /3
=0.2,0.3,7
We can’t simplify it, therefore L.C.M.is
2x 2x 3x 3x 0.2x 0.3x 7
=15.12

Re: Find the least common multiple of 7.2, 1.08 and 21

Post by Guest » Fri Sep 12, 2014 8:59 pm

7.2 x 105 = 756
1.08 x 700 = 756
21 x 36 = 756
so 756 is a common multiple of all the numbers given
and it is the lowest I can find.

Re: Find the least common multiple of 7.2, 1.08 and 21

Post by john » Fri Sep 12, 2014 5:20 pm

L.C.M. for the 3 numbers is 15.12

Re: Find the least common multiple of 7.2, 1.08 and 21

Post by Guest » Tue Sep 09, 2014 8:55 am

answer = 756

Re: Find the least common multiple of 7.2, 1.08 and 21

Post by malikadil » Tue Sep 09, 2014 7:20 am

4 . [tex]\frac{7}{8} = \frac{7}{2} = 3.5[/tex]

Re: Find the least common multiple of 7.2, 1.08 and 21

Post by adamsmith » Tue Jul 02, 2013 3:49 am

The LCM of 7.2, 1.08 and 21 is 21

Re: Find the least common multiple of 7.2, 1.08 and 21

Post by Guest » Fri Jun 21, 2013 7:13 am

Its 10.08

Find the least common multiple of 7.2, 1.08 and 21

Post by Guest » Sun Dec 02, 2012 4:10 pm

Find the least common multiple of 7.2, 1.08 and 21

Top

cron