In a class of 30 students, 5 students did not borrow any books from the library, 12 students each borrowed 1 book, 8 students each borrowed 2 books, and the rest of the students each borrowed at least 3 books. If the average (arithmetic mean) number of books borrowed per student was 2, what is the maximum number of books that any single student could have borrowed ?  Pick.
A) 5	B) 8	C) 15	D) 18	E) 20
The average number of books per student was 2means that total of   2*30= 
<gadget id="calculator">  2*30</gadget>
<output>60</output>
60 books were borrowed;   5+12+8= 
<gadget id="calculator">5+12+8</gadget>
<output>25</output>
25 students borrowed total of  5*0+12*1+8*2= 
<gadget id="calculator"> 5*0+12*1+8*2</gadget>
<output>28</output>
28 books;   So  60-28= 
<gadget id="calculator"> 60-28</gadget>
<output>32</output>
32 books are left to distribute among 30-25= 
<gadget id="calculator">30-25</gadget>
<output>5</output>
5 students, these 5 arethe rest who borrowed at least 3 books;   Tomaximizethe number of books one student from above 5 could have borrowed we shouldminimizethe number of books other 4 students from 5 could have borrowed. Minimum these 4 students could have borrowed is 3 books per student, so total number of books they could have borrowed is 4*3= 
<gadget id="calculator">4*3</gadget>
<output>12</output>
12 books. So the 5th student could have borrowed is  32-12= 
<gadget id="calculator"> 32-12</gadget>
<output>20</output>
20 books.   Answer: 20.
<result>E</result>
In a class of 30 students, 5 students did not borrow any books from the library, 12 students each borrowed 1 book, 8 students each borrowed 2 books, and the rest of the students each borrowed at least 3 books. If the average (arithmetic mean) number of books borrowed per student was 2, what is the maximum number of books that any single student could have borrowed ?