Telsa Motors stock could have been purchased in $5.38 in 2012.  Fast forward, 9 years later the stock is worth $736.24.  What is the annual average rate of return of this stock over the period?  (XX%)

B. Billie Eilish wants to retire from her lucrative career 10 years from now.  She is now looking at a different spending plan from her retirement 10 years from now.   At retirement, for the first 8 years, she spends $350,000 per year at the end of the year, but then she steps back to $250,000  per year for the next 30 years at the end of the period.  

How much she have to save each year during the next 10 earning years ,if earns 6.2% and all payments are at the end of the year?