Task: Question Answering
Input (English): Problem: a certain store sold pens for $ 0.35 each and pencils for $ 0.25 each . if a customer purchased both pens and pencils from the store for a total of $ 1.80 , what total number of pens and pencils did the customer purchase ? 
Options: a ) 6 , b ) 9 , c ) 10 , d ) 11 , e ) 12
Output (English): a