Quant Analysis.

Arithmetic Progression and Geometric Progression.

There is a fixed difference between two numbers of an A.P.

The nth number of an A.P = a+(n-1)d

here a is the first term, d is the difference.

The sum of n terms of an A.P = n/2 ( 2a+ (n-1) d )


In a gemetric Progression the next number is found by multiplying the previous number with a fixed number. This number is called common ratio.

a geometric sequence is a ar ar2 ar3 ...

the nth term is ar raised to (n-1)


Sum of n terms is a( 1 - r raised to n ) / ( 1- r )


Please also remember that if r < 1 (-1 < r < 1 ) then sum of infinite numbers in the sequence = a / 1-r