Question 990447:  Hay's Linens sells hand towels in sets of 10 and bath towels in sets of 6. If the store sold the same number of each [LCM] type of towel that the store must have sold?  
 Answer by KMST(5328)      (Show Source): 
You can  put this solution on YOUR website! Selling hand towels in sets of   , the number of hand towels sold must be a multiple of   . 
Selling bath towels in sets of   , the number of hand towels sold must be a multiple of   . 
If the store sold the same number of each type of towel, 
that same number of each type of towel sold must be a multiple of   , and   . 
The smallest possible number of each type of towel sold is the least common multiple (LCM) of   , and   . 
That number is   . 
Of course, the store may have sold 
  of each type of towel, or 
  , or   , or ...
 
 
HOW TO FIND THE LCM: 
1) We could list the multiples of one of the numbers (preferably the largest). 
The multiples of   are: 
  ,   ,   ,   , ... 
Then we would check then one by one, from smallest to largest, 
to see if we can find a multiple of the other number(s). 
In this case,   , and   are not multiples of   , 
but   is, so   is the LCM of   , and   . 
2) Sometimes the method above does not give you the answer fast enough. 
A more general method involves finding the prime factorizations. 
The prime factorizations of   , and   are 
  and   . 
The prime factorization of the LCM includes all prime factors found in the numbers, with the greatest exponents (if any). 
In this case, 
  , 
  | 
 
  
 
 |   
 
 |