Walking across campus, a student interviewed a group of students. 25% of the students took a finance class last semester, 45% took a marketing class last semester, and 50% took neither a finance nor a marketing class last semester. What percent of the students in the group took both a finance and a marketing class? Choose the correct choice from the following choices.
A) 60% B) 50% C) 20% D) 15% E) 10%
{Total} = {finance} + {marketing} - {both} + {neither}   100 = 25 + 45 - {both} + 50   {both} = 20%.   The answer is 20%.
<result>C</result>
Walking across campus, a student interviewed a group of students. 25% of the students took a finance class last semester, 45% took a marketing class last semester, and 50% took neither a finance nor a marketing class last semester. What percent of the students in the group took both a finance and a marketing class?