Write the set notation

Question

Write the set notation for the set of natural numbers greater than or equal to 1 and less than 125

 

 the set notation for the set of natural numbers greater than 1 and less than or equal to 75 that are multiples of 5. Explain your reasoning. 

Answer 1

  the set will be like this

 

here is a website that gives the simple idea of how to make a set

 

http://www.mathwords.com/s/set_builder_notation.htm
 

 

either one should be fine

 

{1,2,3,...,123,124} = {x| x∈ Ν, 1≤x<125} where N is the natural number

 

 

{5,10,15,20,25,30,35,40,45,50,55,60,65,70,75} = {5x|  x∈ Ν and 1≤x≤15}

 

to find the boundary 1≤x≤15 for this part, it needs the min and the max number in the set, which is 5 and 75, respectively.

set the formula to get the x value (boundary)

5x = 5  so x = 1

5x = 75 so x = 15