The cost of one pencil is $3, and the total cost of three pencils is $9. Which of the following is true?
A. The number of pencils and the total cost are in a proportional relationship because the cost increases with the number of pencils.
B. The number of pencils and the total cost are in a proportional relationship because the cost does not increase with the number of pencils.
C. The number of pencils and the total cost are in a proportional relationship because the cost of zero pencils is $0, and each pencil costs $3.
D. The number of pencils and the total cost are in a proportional relationship because the cost of zero pencils is $0 and it does not increase proportionally with the number of pencils.
Step-by-step explanation: A would be the second best answer but, it does not specify how much it increases by or, if its a steady rate. Therefor C is the best answer because it specificys the unit rate,and why it's proportional.
