The dimensions of each book in an encyclopedia set measures 8 in x 4 in x 12 in. (l x w x h). Each shelf (i.e. each divider) has a surface area of 848 sq in., where the thickness is 1 in and the width is 16 in. Assuming there is enough space in between shelves, how many shelves are needed to fit all of the books?
Choose one
A) 7	B) 12	C) 13	D) 5	E) 26
Surface area of each shelf= 2ab + 2ac + 2bc   848 = 2 x 1 x 16 + 2 x 1 x c + 2 x 16 x c   848 = 32 + 2c + 32c   816 = 34c   c = 24 in. (i.e. the length of each shelf)   Each book is 4 in thick   24/4= 
<gadget id="calculator">24/4</gadget>
<output>6</output>
6 books per shelf   26/6= 4.333=5 shelves   Answer is 5
<result>D</result>
The dimensions of each book in an encyclopedia set measures 8 in x 4 in x 12 in. (l x w x h). Each shelf (i.e. each divider) has a surface area of 848 sq in., where the thickness is 1 in and the width is 16 in. Assuming there is enough space in between shelves, how many shelves are needed to fit all of the books?