logo

Ask Questions, Get Answers

 
X
 Search
Want to ask us a question? Click here
Browse Questions
Ad
Home  >>  JEEMAIN and AIPMT  >>  Mathematics  >>  Class11  >>  Sequence and Series
0 votes

Sum of n terms of the series $\large\frac{1}{4}+\large\frac{7}{16}+\large\frac{37}{64}+\large\frac{175}{256}$+... is

$(a)\;n-3^{-n}+1\qquad(b)\;n-4^{-n}+3^{-n}\qquad(c)\;n-3(1-(\large\frac{3}{4})^n)\qquad(d)\;n-((\large\frac{4}{3})^n-1)$

Can you answer this question?
 
 

1 Answer

0 votes
Answer : (c) $\;n-3(1-(\large\frac{3}{4})^n)$
Explanation : $\;r^{th}\;term\;of\;series$
$a_{r}=1-(\large\frac{3}{4})^r$
$S=\sum_{r=1}^{n}\;1-(\large\frac{3}{4})^r$
$=n-\large\frac{\large\frac{3}{4}(1-(\large\frac{3}{4})^n)}{1-\large\frac{3}{4}}$
$=n-3(1-(\large\frac{3}{4})^n)\;.$
answered Jan 23, 2014 by yamini.v
 

Related questions

Ask Question
student study plans
x
JEE MAIN, CBSE, NEET Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App
...