Multiple Choice Question

Question

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

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 determine the correct statement about the relationship between the amount of money the student makes and time in days, let's analyze the points given in the graph:

• At day 0, the student makes $20 (point (0, 20)).
• At day 1, the student makes $30 (point (1, 30)).
• At day 2, the student makes $40 (point (2, 40)).

From this data, we can see that:

1. The starting amount when no days have passed (intercept) is $20.
2. The increase in money from day to day (slope) appears to be $10 per day.

So, the student's fee structure can be modeled with the formula:

Total Fee = Initial Fee + (Daily Charge * Number of Days)

From the analysis:

• Initial Fee: $20
• Daily Charge: $10

Putting this into the formula gives us:

Total Fee = $20 + $10 * (number of days)

The relationship described fits with option C:

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

Therefore, the correct answer is C.