N1D8TNp19

 

Answer to Problem 19:

Possible answers are 3, 9, 15,…   any number divisible by 3 but not by 4, 6, or 12

 

TEACHER  NOTE:

In order for a number, which is divisible by both a and b to be divisible by ab, a and b must be relatively prime. To be relatively prime, two numbers must have a greatest common factor of 1. Since 3 and 6 have a greatest common factor of 3, they are not relatively prime.

 

 

DEFINITION:

 

factor:  an integer that will divide evenly into another number (the quotient has a remainder of 0).  1, 2, 3, 4, 6, 12 are all factors of 12, since 12 is divisible by each.[1]

multiple:  the product of a whole number and any other whole number.     Multiples of 5 include 0, 5, 10, 15, … etc.[2]


 

[1] Math at hand: A mathematics handbook (p. 524). (1999).  Wilmington, MA: Great Source Education Group, Inc.

[2] Math on call: A mathematics handbook (p. 584). (1998). Wilmington, MA: Great Education Source Group, Inc.