Almost 90% of the companies include quantitative aptitude section in their placement tests. Since the time given would be limited it is important you remember formulas. They are sure to help you by saving a lot of time.
Arithmetic and Geometric ProgressionCompanies like TCS, HCL, Wipro, Accenture etc. and a lot of other companies include at least a couple of questions from arithmetic and geometric progressions.
Believe AP and GP Questions Are Not Tough!Questions like find a missing number, fill the missing dash etc., would generally be from AP and GP sections. Though they might look hard to solve at first glance, they are very easy to tackle if you remember few miscellaneous formulas.
Let us look into definition and important formulas for both arithmetic and geometric progressions.If you are looking for formulas for other sections of quantitative aptitude, I would recommend a FREE Facebook Formulas handbook which you can get at the page http://www.facebook.com/pages/CareersValley/143704715641819?v=app_4949752878
Definition: If each term of a series differs from its preceding term by a constant, then such a progression is called arithmetic progression.
e.g: 2,5,8,11In the above sequence the difference between any two terms in 3.
Formula:
Consider an AP : a, (a + d), (a + 2d), (a + 3d),(a + 4d),....
1) n th term of the above sequence = Tn = a + (n - 1)d
2) Sum to n no of terms Sn = n / 2 (2a + (n - 1)d)
3) Another formula for Sn = n / 2 (first term + last term)
Definition: Any progression or sequence with successive terms having a common ration is called geometric progression.
e.g: 2,4,8,16...In the above sequence the common ratio is 2 for any two successive terms
Formula
Consider a GP - a, ar, ar2.... where a is the first term and r is the common ratio
4) n th term, Tn = arn-1
5) Sum to n terms , Sn = a(1 - rn)/(1-r)
6) In case r lies beween -1 and +1 then Sum of all terms of the series = a/(1 - r)
FREE Formulas Handbook In Facebook Page FormatFor a complete list of formulas from sections of quantitative aptitude, I would recommend a FREE Facebook Formulas handbook which you can get at the page http://www.facebook.com/pages/CareersValley/143704715641819?v=app_4949752878

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