Problem Solving

The pages of a report are numbered
consecutively from 1 to 10. If the sum
of the page numbers up to and
including page number x of the report
is equal to one more than the sum of
the page numbers following page
number x, then x =
(A) 4 (B) 5 (C) 6 (D) 7 (E) 8

grandh01 wrote:The pages of a report are numbered
consecutively from 1 to 10. If the sum
of the page numbers up to and
including page number x of the report
is equal to one more than the sum of
the page numbers following page
number x, then x =
(A) 4 (B) 5 (C) 6 (D) 7 (E) 8

find the sum of numbers from 1 to 10: 55
Divide 55 by 2 : 27.5
Therefore the sum of numbers up to x = 28 and the sum of numbers after x = 27

Subtract 10,9,8,..., 1 from 27 in this order
What ever number gives a difference of 0 is equal to x+1

10: 27 - 10 = 17
9 : 17 - 9 = 8
8 - 8 = 0

x+1 = 8
x = 7
ans = d