Answer:
The 15 books is smarter
Step-by-step explanation:
First, you have to evaluate your circumstances.
You can buy 11 books for 99 dollars, so when you do 99/11, you get
1 book per 9 dollars.
You can buy 15 books for 105 dollars, which when you do 105/15,
you get 1 book per 7 dollars.
Therefore, getting 15 books for 105 dollars is better because you
pay 2 less dollars.
Hope this helps! <3
