Home » Ask & Discuss » Mathematics. » Algebra « Back to Discussion

Algebra

Cool goIITian

Joined:	20 Oct 2008
Post:	45

15 Jul 2009 17:27:57 IST

0 People liked this

560

7. 0.15, 0.015, 0.0015, ... 20 terms. find sum of G.P. ans is 1/6[1-(0.1)^20] . wrking

None

7. 0.15, 0.015, 0.0015, ... 20 terms. find sum of G.P. ans is 1/6[1-(0.1)^20] . wrking

Share this article on:

Comments (3)

®µD®A

Blazing goIITian

Joined: 12 Apr 2008

Posts: 2717

15 Jul 2009 18:19:20 IST

Like 1 people liked this

$S_n=\frac{a(1-r^n)}{1-r}$

$S_{20}=\frac{0.15(1-0.1^{20})}{1-0.1}$ $=\frac{1.5(1-0.1^{20})}{9}$ $=\frac{(1-0.1^{20})}{6}$

Aakash Anuj

Blazing goIITian

Joined: 26 Mar 2009

Posts: 1428

15 Jul 2009 22:58:52 IST

Like 1 people liked this

quite simple. Rudra is correct

Bipin Dubey

Forum Expert

Joined: 23 Jan 2007

Posts: 7942

17 Jul 2009 14:56:33 IST

Like 0 people liked this

It is a direct formula based question where a=0.15, r=0.1 and n=20.

Quick Reply

Reply

	Some HTML allowed.
	Keep your comments above the belt or risk having them deleted.
	Signup for a avatar to have your pictures show up by your comment
	If Members see a thread that violates the Posting Rules, bring it to the attention of the Moderator Team

Free Sign Up!

Preparing for IIT-JEE ?

Arihant Revision Package for IIT JEE - Books, Practice Tests + Rank Predictor

@ INR 1,995/-

For Quick Info

Find Posts by Topics

Physics.

Topics

9389

20086

3671

2185

7614

2826

2634

Mathematics.

Chemistry.

Biology

Institutes

Parents

Board

Fun Zone