Task: Question Answering
Input (English): Problem: on a purchase of $ 110 , a store offered a payment plan consisting of a $ 10 down payment and 12 monthly payments of $ 10 each . what percent of the purchase price , to the nearest tenth of a percent , did the customer pay in interest by using this plan ? 
Options: a ) 9.5 % , b ) 10.5 % , c ) 11.5 % , d ) 9.1 % , e ) 12.5 %
Output (English): d