Task: Question Answering
Input (English): Problem: money invested at x % , compounded annually , triples in value in approximately every 112 / x years . if $ 2000 is invested at a rate of 8 % , compounded annually , what will be its approximate worth in 28 years ? 
Options: a ) $ 3,750 , b ) $ 5,600 , c ) $ 8,100 , d ) $ 18,000 , e ) $ 22,500
Output (English): d