Hi all,
sometimes I came across great posts that I would like to collect in one place. These posts not only provides basic information but also provide different approaches.

Odd/even -- http://gmatclub.com/forum/odd-even-95982.html
Integer -- http://gmatclub.com/forum/x-3-an-integer-94471.html#p748688
sum of consecutive integers -- http://gmatclub.com/forum/ds-sum-of-integers-90974.html
variable expression -- http://gmatclub.com/forum/what-is-the-value-of-x-87140.html
How to factorize large number -- http://gmatclub.com/forum/determining-factorizations-of-a-number-94131.html
Absolute value basic-http://gmatclub.com/forum/abs-equation-from-gmatprep-84821.html
ABSOLUTE VALUE INEQUALITIES and SQUARE INEQUALITIES --http://www.manhattangmat.com/forums/if-x-is-positive-is-x-3-t10421.html
Absolute value with "check point" method --http://gmatclub.com/forum/some-inequalities-questions-93760.html
Absolute value with "distance on number line" approach--http://gmatclub.com/forum/math-ds-87926.html
Equation and inequality (using substitution) --http://gmatclub.com/forum/ds1-93964.html
Squaring inequalities -- http://gmatclub.com/forum/interesting-inequality-96147.html
COORDINATE GEOMETRY
circle with inscribed triangle --http://gmatclub.com/forum/cord-geometry-42105.html
Straight lines --http://gmatclub.com/forum/og-12-ds-question-line-concept-very-good-one-key-wrong-89300.html
Circle+distance+triangle properties --http://gmatclub.com/forum/gmatclub-hardest-questions-co-geometry-q1-92566.html
Corresponding points in 4 quadrants --http://gmatclub.com/forum/plane-geometry-semicircle-from-gmatprep-85154.html

Maximum area of a triangle --http://gmatclub.com/forum/gmat-prep-ps-93779.html
Triangle: ratio of areas / ratio of sides --http://gmatclub.com/forum/gmat-prep-ps-93779.html
Triangle and median line --http://gmatclub.com/forum/ps-shaded-area-is-half-the-triangle-97286.html
triangle and circle --http://gmatclub.com/forum/geometry-question-regarding-circle-and-triangle-92274.html
central angle theorem --http://gmatclub.com/forum/ps6-93977.html
Cubic graph --http://gmatclub.com/forum/equation-of-the-graph-82212.html

work rate 1 --http://gmatclub.com/forum/what-am-i-doing-wrong-to-bunuel-91124.html?highlight=rate+reciprocal
work rate 2 --http://gmatclub.com/forum/facing-problem-with-this-question-91187.html?highlight=rate+reciprocal
Kudos are much appreciated

Thanks for sharing them
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