Question

The fine schedule for overdue books at the county library is modeled by the values in the table.

Library Fines for Overdue Books
Days overdue
Amount of fine
0
0 ¢
2
5 ¢
4
10 ¢
6
15 ¢
8
20 ¢
10
25 ¢

Which equation best models the fine schedule for overdue books?
y = five-halves x, where x is the cost in cents for a book that is y days overdue
y = five-halves x, where y is the cost in cents for a book that is x days overdue
y = 5 x, where x is the cost in cents for a book that is y days overdue
y = 5 x, where y is the cost in cents for a book that is x days overdue

Answer 1

y = five-halves x, where y is the cost in cents for a book that is x days overdue

Reason: The fine increases 5¢ every 2 days, so rate = 5/2 = 2.5¢ per day, i.e. cost (y) = (5/2)·days (x).