I need help with this ASAP

Super ultra mega important if you can answer this correctly i will give you 100 points but if you don't answer it correctly you'll get a big report. so stay aware and have a nice day!

Which recursive formula can be used to determine the total amount of money earned in any year based on the amount earned in the previous year? f(n+1)=f(n)+5

45% of the trees in a park are apple trees. there are 27 apple trees in the park. how many trees are in the park in all?