clear and complete solutions

1. How long will it take money to triple itself if invested at 5% compound interest rate? 2. By the condition of a will, the sum of P20,000 is left to a girl to be held in a trust fund by her guardian until it amounts to P50,000. When will the girl receive the money if the fund is invested at 8% compounded quarterly? 3. If P500,000 is deposited at a rate of 11.25% compounded monthly, determine the compounded interest after seven years and nine months