# Progression Sum

• Jan 30th 2010, 10:56 AM
findmehere.genius
Progression Sum
The question states:
what would be sum of
$\displaystyle 1+1/3^2 +(1*4)/((1*2)*3^4) +(1*4*7)/((1*2*3)*3^6) +......$

and since the question is multiple choice type:
a)$\displaystyle (3/2)^(1/2)$ 3/2 power 1/2
b)$\displaystyle (3/2)^(1/3)$ 3/2 power 1/3
c)$\displaystyle (1/3)^(1/2)$ 1/3 power 1/2
d)$\displaystyle 1/2^(1/2)$ 1/ root 2

My head is boggled....question came in test...took a lot of my time even at home, plz help.
• Jan 30th 2010, 11:09 AM
General
Quote:

Originally Posted by findmehere.genius
The question states:
what would be sum of
$\displaystyle 1+1/3^2 +(1*4)/((1*2)*3^4) +(1*4*7)/((1*2*3)*3^6) +......$

and since the question is multiple choice type:
a)$\displaystyle (3/2)^(1/2)$ 3/2 power 1/2
b)$\displaystyle (3/2)^(1/3)$ 3/2 power 1/3
c)$\displaystyle (1/3)^(1/2)$ 1/3 power 1/2
d)$\displaystyle 1/2^(1/2)$ 1/ root 2

My head is boggled....question came in test...took a lot of my time even at home, plz help.

Are you mean this?:
$\displaystyle 1+\frac{1}{3^2}+\frac{(1)(4)}{(1)(2)(3^4)}+\frac{( 1)(4)(7)}{(1)(2)(3)(3^6)}+.....$