Task: Question Answering
Input (English): Problem: sara bought both german chocolate and swiss chocolate for some cakes she was baking . the swiss chocolate cost $ 3.5 per pound , and german chocolate cost $ 2.5 per pound . if the total the she spent on chocolate was $ 70 and both types of chocolate were purchased in whole number of pounds , how many total pounds of chocolate she purchased ? 
Options: a ) 7 , b ) 8 , c ) 10 , d ) 24 , e ) 15
Output (English): d