Answer = $160
Using the formula 100+4n, we need to substitute 15 with n. Therefore making the formula, 100 + 4×15. 4×15 = 60. 60+100= $160.
-Hope it helps!
You have to multiply by how many months or boxes and your gonna have 360 and your friend 288
Posting screenshot of my answer in the linked question in case it gets deleted.
