Kendall can buy a maximum of 13 notebooks and 13 pens with $40.
To find the maximum number of notebooks and pens Kendall can buy with $40, we first need to determine the price of each item. Let's assume the price of a notebook is $2 and the price of a pen is $1. Since Kendall wants to buy an equal number of notebooks and pens, we can divide her budget of $40 by the total price of one set, which is $2 + $1 = $3.
Therefore, Kendall can buy a maximum of 40 ÷ 3 = 13 sets of notebooks and pens. Since each set includes one notebook and one pen, she can buy a maximum of 13 notebooks and 13 pens.