The relationship between the number of hours a plumber works and the total work fee she charges is proportional. Her fee for 5 hours of work is $350. Which of the following could be combinations of values for the plumber's work hours and total work fee she charges?

Solution:As given,  relationship between the number of hours a plumber works and the total work fee she charges is proportional. The meaning of proportional is Ratio of number of hours a plumber works and the total work fee she charges is constant.Using Unitary method5 hours of work = $3501 hours of work = $70Let number of hours worked = x hoursAmount earned for x hours of work is represented by = $ yFor , x hours of work amount earned = 70 x (x=1,2,3...)→y= 70 x→→[tex]\frac{x}{y}=\frac{1}{70} \text{or} \frac{y}{x}=70[/tex]