Task: Question Answering
Input (English): Problem: daniel went to a shop and bought things worth rs . 50 , out of which 90 paise went on sales tax on taxable purchases . if the tax rate was 15 % , then what was the cost of the tax free items ? 
Options: a ) a ) 19.7 , b ) b ) 20 , c ) c ) 43.1 , d ) d ) 21.5 , e ) e ) 22
Output (English): c