First I calculate in how many weeks Caroline will get 80$
4$*20 weeks =80$
but Caroline had 20$ at the beginning which means in 20 weeks she will have collected 80$+ 20$= 100$
the answer is after 20 weeks Caroline will have more than 100$in her bank .
Question, I that the Algebra nation book????
Answer: 5, 268 ft
Based on a quick internet search.