In order to complete a reading assignment on time, Terry planned to read 120 pages per day. However, she read only 60 pages per day at first, leaving 840 pages to be read during the last 6 days before the assignment was to be completed. How many days in all did Terry have to complete the assignment on time? Answers:
A) 4	B) 6	C) 8	D) 10	E) 12
D=120*X - according to the plan, assignment to be completed on time reading 120 pages per day for next X days. But, Terry's plans changed so she read as follow:   60 pages for first Y days and 780 pages for last 6 days, we get these equations:   60*Y+840=120*X   X-Y=6 ---------&gt;&gt;X planned number of days, Y - actually used reading 60 pages per day and 6 leftover days used to complete a lump 780 pages   From above we find that X=Y+6 and 60Y+840=120Y+720 or 60Y=120 ---&gt;&gt;&gt;&gt;&gt; Y=2, hence X=8   Answer : 8
<result>C</result>
In order to complete a reading assignment on time, Terry planned to read 120 pages per day. However, she read only 60 pages per day at first, leaving 840 pages to be read during the last 6 days before the assignment was to be completed. How many days in all did Terry have to complete the assignment on time?