Task: Question Answering
Input (English): Problem: two years ago , john put $ 5000 into a savings account . at the end of the first year , his account had accrued $ 500 in interest bringing his total balance to $ 5500 . the next year , his account balance increased by 10 % . at the end of the two years , by what percent has john ' s account balance increased from his initial deposit of $ 5000 ? 
Options: a ) 19 % , b ) 21 % , c ) 20 % , d ) 22 % , e ) 25 %
Output (English): b