Yes
Prime numbers help you to find the LCM and the GCF.
You need at least two numbers to find an LCM no matter what you use.
Prime factor both numbers and use the numbers the number of times it is used the most in either number. In this case the LCM is 600.
It doesn't matter which method you use. You still need at least two numbers to find an LCM. There is no LCM of 20.
That's a false statement. Both 16 and 64 have one prime factor. 16 can't be the LCM of two prime numbers and 64 can't be the product. If you leave out the word prime, you can use 16 and 4.
In finding the LCM or HCF of two or more numbers
It is the same as finding the LCM of two numbers that have been expressed as a product of their prime factors except that you need to use the highest index for each prime factor.
To figure out the LCM you should first find out how your number should be written using it's prime factors.Eg. 28=2x2x7 as all these numbers are prime#24=2x2x2x3The LCM will then be the product of these numbers you have just found(note. for 28 you have 2x2 and for 24 you have 2x2x2. It is not necessary to use 2x2x2x2x2. all you need to have is 2x2x2 as this is the largest amount of that number used to make up 24 or 28.)eg. LCM = 2x2x2x3x7=168Hopefully that helps and is not too confusing!
Prime factor both numbers and then use them the MOST it was used in either number. 5=5 19=19 5x19=95
Take the denominators and factor them into prime numbers. The LCM is the product of the prime numbers that were used the most. Here is an example. 1/30 and 1/24 30=2x3x5 24=2x2x2x3 LCM=2x2x2x3x5=120 Use that as the common denominator and multiply the numerator by the amount needed to multiply the denominator by to get the LCM.
3 x 5 = 153 x 7 = 213 x 5 x 7 = 105, the LCM
a and b have no common prime factors. Their LCM is their product.