That seems like a fairly easy choice...
The answer will depend on the problem!
yes because it helps me figure out all the prime numbers!;)
you list all the multiples of each number until you come to the first number that is in all columns
This cannot be answered because the common multiples of any two or more numbers are infinite.
The hcf is useful in reducing fractions to their lowest terms and the lcm is useful in finding the lowest common denominator of fractions that have different denominators that need to be added or subtracted.
Factors,are the number that can be multiply and multiplies are the operation to solve a problem and to factorize numbers...
There are two: whether there is a need for their invention, and is their invention original.
21 and 84
The main one is whether SEX is a gud choice or not !
The way to solve this is as follows:Find the least common multiple of the two numbers.Multiply this least common multiple by 2 and by 3, to get the next two common multiples.
the least common multiple is what the numbers you are using divide into. e.g. 3 and 6 have 12 as the common factor. the greatest common factor is what divides into your numbers. 6 and 9 have 3 as the greatest common factor
There is not enough information to solve the problem.