1. Suppose you invested P 641,158 in a fund earning 9 % simple interest annually. After 2 years, you have the option of moving your money to an account that pays at an annual effective rate of 8 % compound interest. If you wish to withdraw in 8 more years, determine the net benefits of staying your money in the simple interest account. 

2. Suppose that the growth of money is governed by 5 % simple interest. Find the amount needed to invest in order to have a balance of P 12,582,910 18 years from now. 

3. Mr. Business Finance inherited P 3.021,351. He deposited it in a five-year investment paying 6 % nominal interest compounded. At the end of five years, he decided to renew the investment for another five years at the current nominal interest rate compounded of 9 %. Find his return on investment at the end of his investment's maturity. 

4. You are planning to invest P 5,896.001 in a bank with 6 % simple interest. Find the time (in years) needed to make it P 31,969,327