How to calculate compound interest and figure out how much to deposit in a time deposit to get a certain amt?

I wanted to provide for an education for my child. I will need a minimum of P400,000 in ten years time for her high school education. How much do I need to contribute quarterly, for five years, to a time deposit with an interest of 2.875% per annum, to be able to achieve the goal of P400,000 in ten years time? I tried to look for formulas on the web without much success....|||You have to set aside P 8,606 per quarter to make P 400,000 in ten years.





Quarter Amount Interest Balance





1860662 8668


28606124 17398


38606187 26191


48606250 35047


58606314 43967


68606378 52951


78606442 61999


88606507 71113


98606573 80292


108606639 89536


118606705 98848


128606772 108226


138606840 117672


148606908 127186


158606976 136768


1686061045 146418


1786061114 156139


1886061184 165929


1986061254 175789


2086061325 185721


2186061397 195723


2286061469 205798


2386061541 215945


2486061614 226165


2586061687 236458


2686061761 246826


2786061836 257268


2886061911 267785


2986061987 278377


3086062063 289046


3186062139 299791


3286062217 310614


3386062294 321514


3486062373 332493


3586062452 343551


3686062531 354688


3786062611 365905


3886062692 377203


3986062773 388582


4086062855 400043





I am attaching the chart with the quarterly balances in the 40 quarters over the 10 years.