Ms. Lang determines her children’s allowance based on the following situations: The amount of money they each receive in a week is directly proportional to the number of hours of work they each have done in the yard and inversely proportional to $5$ – GPA where GPA is the grade point average from the last report card. Dana received $$14.40$ this week. Her last report card had a GPA of $3.5$ and she worked $10$ hours in the yard during the week.

1. Write the formula that Ms. Lang uses to determine the amount of money she will give each child each week.

   Step (a):

   $A=\frac{kw}{5 - \text{GPA}}$

   Now compute the value of $k$ using the given information.

2. This week Kaitlyn worked $15$ hours in the yard and received $$20$. What was her GPA from her last report card?

   Hint (b):

   Use the equation from part (a).