Question

Janie receives an allowance of $3 per week. In addition, she can earn $2 for each chore she does. This week, she wants to earn enough money to buy a CD for $13. Janie can do fractions of chores.

Answer 1

she could earn $13 in one week. She has to do at least 10 chores. 

Answer 2

Let us say that the number of weeks is "x" and the number of chores is "y".

If we state an algebraic expression for Janie's allowance it would be

3x+2y=13

However, there are two variables, hence many answers. To solve this problem, there must be more information about the relation between x and y.