Hi guys need help for subject theory of interest

An investment of P100,000 is to be used to make payments of P 4,000 at the end of each quarter for as long as possible. If the rate of interest is 5% convertible quarterly, find: (a) the number of regular payments the fund will make, and number of days from the last payment to the exact date using exact time, assuming leap year on the last payment (b) the size of the smaller final payment if the payment will be made in addition to the last regular payment, (c) the size of the smaller final payment if the payment will be made one year after the last regular payment. (d) the size of the smaller final payment if the payment is to be made during the year following the last regular payment. An investment of P100,000 is to be used to make payments of P 4,000 at the end of each quarter for as long as possible. If the rate of interest is 5% convertible quarterly, find: (a) the number of regular payments the fund will make, and number of days from the last payment to the exact date using exact time, assuming leap year on the last payment (b) the size of the smaller final payment if the payment will be made in addition to the last regular payment, (c) the size of the smaller final payment if the payment will be made one year after the last regular payment. (d) the size of the smaller final payment if the payment is to be made during the year following the last regular payment