The marked questions ? are right ones. I need the steps and explaination

14. At 18.9% percent compounded annually, $50,000 will double in about: a. 6.5 years 4 years c. 9 years d. 12 years e. none of the above L5. Charlie wants to retire in 30 years, and he wants to have an annuity of $1,000 year for 20 years after retirement. Charlie wants to receive the first annuity payment at the end of the 30th year. Using an interest rate of10%how much must Charlie invest today in order to have his retirement annuity (round to the nearest $10). a. $500 b. $490 $540 d. $570 none of the above X 16. A customer has a margin account with a market value of $20.000, a debit balance of $ 12,000 and no SMA. Reg T is 50% and if the customer sells S2.000 worth of stock, the amount that can be withdrawn in cash is: a. S 500 $ 1,000 S 2,000 S 8,000