Given data: 3 hours of work for 12 dollars and 9 hours of work for 36 dollars.
 Question : Let us show the unit rate of each given data, then solve for the unit rate. Which of the two is better?
 Solutions:
 First given = 3 hours of work for 12 dollars
 => 12 dollars to be divided with 3 hours
 => 12 / 3 = 
 => 4 dollars / hour
 Then let’s solve for the second given data = 9 hours of work for 36 dollars
 => 36 dollars will be divided with 9 hours of work
 => 36 / 9 = 4 dollars
 => 4 dollars / hour
 Thus, the first and the second given data are equal