Task: Question Answering
Input (English): Problem: a certain automobile company ’ s best - selling model is the speedster . the speedster , like all of their other models , comes in coupe and convertible styles . 1 / 3 of the current inventory is speedsters , of which 4 / 5 are convertibles . if there are 30 vehicles that are not speedsters , how many speedster convertibles are there ? 
Options: a ) 13 , b ) 18 , c ) 12 , d ) 15 , e ) 17
Output (English): c