Task: Question Answering
Input (English): Problem: sara bought both german chocolate and swiss chocolate for some cakes she was baking. the swiss chocolate cost $ 2.5 per pound, and german chocolate cost $ 1.5 per pound. if the total the she spent on chocolate was $ 30 and both types of chocolate were purchased in whole number of pounds, how many total pounds of chocolate she purchased ?
Options: a. 7, b. 18, c. 10, d. 12, e. 11
Output (English): b