Pages

Labels

Contributors

Powered by Blogger.

Thursday, 19 June 2014

Quantitative Aptitude - Formulae - A.P & G.P

Arithmetic Progression (A.P):

An A.P. is of the form a, a+d, a+2d, a+3d, ...


where a is called the 'first term' and d is called the 'common difference'


nth term of an A.P. tn = a + (n-1)d


Sum of the first n terms of an A.P. Sn = n/2[2a+(n-1)d] or 


Sn = n/2(first term + last term)

Geometrical Progression (G.P):


A G.P. is of the form a, ar, ar2, ar3, ...


where a is called the 'first term' and r is called the 'common ratio'.


nth term of a G.P. tn = ar^(n-1)


Sum of the first n terms in a G.P. Sn = a|1-r^n|/|1-r|



Note : ^ denotes to the power of something here 

0 comments:

Post a Comment