Tom read a book containing 480 pages by reading the same number of pages each day. If he would have finished the book 5 days earlier by reading 16 pages a day more, how many days did Tom spend reading the book?  Choose the correct choice from the following choices:	A) 10	B) 12	C) 15	D) 16	E) 18
Say the number of days Tom spent reading the book was dd. Then:   The number of pages he read per day would be 480/d   The number of pages he would read per day with an increased speed would be 480/d−5   e are told that the number of pages for the second case was 16 pages per day more, so 480/d=480/d−5−16   At this point it's much better to plug answer choices rather than solve for dd. Answer choice 1515 fits:  480/15= 
<gadget id="calculator"> 480/15</gadget>
<output>32</output>
32=480/15−5−16   Answer: 15
<result>C</result>
Tom read a book containing 480 pages by reading the same number of pages each day. If he would have finished the book 5 days earlier by reading 16 pages a day more, how many days did Tom spend reading the book?