Final answer:
Arianna can buy notebooks at a rate of $2.25 per notebook. Marie can purchase a maximum of 6 magazines in a week with her budget of $24, given that each magazine costs $4.
Step-by-step explanation:
The student is asking about the cost per notebook when Arianna purchased 4 notebooks for $9.00. To find this, we simply divide the total cost by the number of notebooks. Therefore, the cost per notebook is $9.00 ÷ 4 notebooks = $2.25 per notebook.
To address the related question, if Marie has a weekly budget of $24 and she wants to spend it on magazines that cost $4 each, we need to find out how many magazines she can buy. We divide her budget by the price of one magazine: $24 ÷ $4 = 6 magazines. Thus, the maximum number of magazines Marie could buy in a week with her budget is 6.