A recently graduated petroleum engineer is able to save 12,000 TL every year from her salary. If she keeps depositing this amount to her savings account, the bank guarantees to apply 20% interest to her savings every year for the next 25 years. She doesn't have any money at the beginning and she is planning to make her first deposit after her first year at work. a) (5 pts) To have a total sum of 2 million TL in her account, for how long she needs to deposit. b) (5 pts) If she wants to have 3 million TL after 20 years of depositing, what should be the interest rate per year? For both problems, draw the cash-flow diagram, indicate given and unknown parameters