Math question What is the L.C.M for numbers 72 and 200is it 1,800?

Yes, it the LCM is 1800.


I'm guessing that you would like to know why, and how you can figure out other questions like this.





Here's how I go about it.


We want to factor each number into all the prime numbers that multiply to create the number.


What's a prime number? Just a number that can't be broken down into two other numbers multiplied together.


I like to start with small numbers (2, 3, 5) and work my way up.


So, 72 can be created by 2*36


Which can be 2*2*18


or 2*2*2*9


or 2*2*2*3*3


and if we check to make sure we didn't make a mistake,


2*2*2*3*3=72





2 and 3 can only be created by multiply themselves by the number 1, so we've broken down 72 as far as it will go.





Now, onto 200.


2*100


2*2*50


2*2*2*25


2*2*2*5*5=200





The Least Common Multiple will be created when we multiply numbers that includes each of the prime numbers that make up 72 and 200.





72 has three 2's and two 3's, so we'll need to use at least that many 2's and 3's.


200 has three 2's and two 5's, so we'll need to use at least those.





But, here's the part that makes this the LEAST Common Multiple, we don't have to use ALL the numbers, just enough so that we have as many as either of the two original numbers.





We need at least three 2's. But we don't need any more than that because neither 72 or 200 have more than three 2's.


We need at least two 3's and we need at least two 5's.





When we multiply 2*2*2*3*3*5*5 we get 1,800.


Yea! You found it!





Good luck.

Math question What is the L.C.M for numbers 72 and 200is it 1,800?
You are correct, the L.C.M. is 1,800. Below is the link to an online calculator.
Reply:yes. it's 1800.
Reply:You are absolutely correct!