Task 1. A customer in a bank withdrew PLN 5000 from a savings account after 3 years. The nominal interest rate was 2.5\%. The deposit lasted 3 years. For the last 9 months a simple interest rate method was used, before that for 15 months a compound interest rate, and at the beginning a continuous compounding interest rate (after each change in the interest rate method the profits were credited to the account balance). Please calculate how much was saved at the beginning of this deposit. Task 2. For the first six months, a certain loan was subject to a continuous interest rate of 6.5%. For the next 15 months it was at a compound interest rate of 7% with quarterly capitalisation. Finally, for one year it was at a compound interest rate of 8.5% with semi-annual capitalisation. Find the average effective interest rate on this loan over the whole analysed