All parts, state the formula you use plz

Uni buys a perpetuity paying $4,000 every three years, starting immediately. She deposits the payments into a savings account earning interest at an effective interest rate of 5%. Twelve years later, before receiving the fifth payment, Uni sells the perpetuity based on an effective annual interest rate of 5%. Using proceeds from the sale plus the money in the savings account, she purchases an annuity paying Pat the end of every two years for twenty years at an annual effective interest rate of 5%. Her savings account balance immediate before the 5th-payment rounded to the nearest dollar is 23,380. Find the balance to the nearest cent. 23380.17 Uni sells the perpetuity for 29,377 rounded to the nearest dollar. Find the sale price to the nearest cent. 29377.14 Find P. Answer to the nearest cent