Mrs. Watson is grading 120 final exams from her American History class.  On Monday, she grades 60% of the exams.  On Tuesday, she grades 75% of the remaining exams.  On Wednesday, how many more exams does she need to grade?
On Monday, Mrs. Watson grades 120 x 60% = 
<gadget id="calculator">120*60*.01</gadget>
<output>72</output>
72 final exams.
At the end of Monday, she has 120 - 72 = 
<gadget id="calculator">120-72</gadget>
<output>48</output>
48 exams left to grade.
On Tuesday, she grades 48 x 75% = 
<gadget id="calculator">48*75*.01</gadget>
<output>36</output>
36 final exams.
On Wednesday, she has 48 - 36 = 
<gadget id="calculator">48-36</gadget>
<output>12</output>
12 exams left to grade.

<result>12</result>