hello! can anyone help me on my assignment?

Our lesson is aboutSolving Problems Involving annuity.

cause I am literally confused on what formula should i use. Between present and future formula.

And what should i choose on between General ordinary annuity or General annuity due

I already done some of my assignments, but this 3 questions are really hard.

I uploaded a picture here with some examples and solutions.

General Ordinary Annuity "Ordinary" means that the payments are made or received at the end of each payment interval "General" means that the payment interval and interest conversion intervals are different Future Value of GOA (FV ord) Present Value of GOA (PV ord) FV ord = R (It iz)"-1 RECALL PV ord = R I - (1+ iz) " 12 Future Value of SOA (Ford) Equivalent Rate of Interest Per Payment Period "i2" Ford = R (1+ 1)" - 1] i2 = (1 +i)c - 1 Present Value of SOA no. of compounding periods (Pord) C = no. of payments per year Pord = R 1- (1+ 1)-" General Annuity Due 0 "Due" means that the payments are made or received at the beginning of each payment interval "General" means that the payment interval and interest conversion intervals are different Future Value of GAD (Fdue) Present Value of GAD (P due) F due = R (1 + iz)" -1 ( 1 + 12 ) Pdue = R 1 - (1+ 12)"" i2 i2 ( 1 + 12 ) RECALL Future Value of SAD Equivalent Rate of Interest Per Payment Period "i2" (F due) i2 = (1 + i)c - 1 Fdue = R (1+1)" - 1 ( 1 +1) no. of compounding periods Present Value of SAD C = - (Pdue) no. of payments per year Pdue = R R 1 - (1+()" (1 + 1)