A student makes money by watching the neighbors’ dog. The situation is modeled in the graph below.

Question

The graph titled money made shows Fee in dollars from 0 to 130 on the y axis in increments of 10 and time in days from 0 to 10 the line passes through the points (0, 20), (1, 30), (2, 40).

Which statement correctly describes the relationship between the amount of money the student makes and time in days?

A. The student charges $11 plus an additional $20 per day.

B. The student charges $20 plus an additional $11 per day.

C. The student charges $20 plus an additional $10 per day.

D. The student charges $10 plus an additional $20 per day.

Answer 1

To describe the relationship between the amount of money the student makes (Fee) and time in days, we can analyze the points given on the graph:

• At day 0, the fee is $20.
• At day 1, the fee is $30.
• At day 2, the fee is $40.

From day 0 to day 1, the fee increases from $20 to $30, which is an increase of $10. Then from day 1 to day 2, the fee increases from $30 to $40, which is again an increase of $10.

This indicates that the fee increases by $10 for each additional day. The initial fee (when time is 0 days) is $20.

Based on this analysis, we can conclude:

• The student charges a flat fee of $20 plus $10 for each additional day.

The correct statement describing this relationship is:

C. The student charges $20 plus an additional $10 per day.