GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 22 Jan 2019, 19:52

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

## Events & Promotions

###### Events & Promotions in January
PrevNext
SuMoTuWeThFrSa
303112345
6789101112
13141516171819
20212223242526
272829303112
Open Detailed Calendar
• ### The winners of the GMAT game show

January 22, 2019

January 22, 2019

10:00 PM PST

11:00 PM PST

In case you didn’t notice, we recently held the 1st ever GMAT game show and it was awesome! See who won a full GMAT course, and register to the next one.
• ### Key Strategies to Master GMAT SC

January 26, 2019

January 26, 2019

07:00 AM PST

09:00 AM PST

Attend this webinar to learn how to leverage Meaning and Logic to solve the most challenging Sentence Correction Questions.

# Algebra - summing up using Sigma notation

Author Message
Intern
Joined: 24 Jan 2018
Posts: 1
Algebra - summing up using Sigma notation  [#permalink]

### Show Tags

24 Jan 2018, 05:35
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 1 sessions

### HideShow timer Statistics

Hi!
I'd be incredibly greatful if you could provide me with a bit deeper explenation of the excercise below than it's in the Official Guide (pls see in the attachment).

"For any positive inteer n, the sum of the first n positive integers equals [n(n+1)][/2] . What is the sum of all the even integers between 99 and 301?"
a) 10,100
b) 20,200
c) 22,650
d) 40,200
e) 45,150

Why exactly does one have to use the sum of the 150 even integers and the substract the sum of the 49?

--== Message from the GMAT Club Team ==--

THERE IS LIKELY A BETTER DISCUSSION OF THIS EXACT QUESTION.
This discussion does not meet community quality standards. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.

Attachments

27394815_1714714351914775_1712151078_n.jpg [ 59.3 KiB | Viewed 173 times ]

Math Expert
Joined: 02 Sep 2009
Posts: 52390
Re: Algebra - summing up using Sigma notation  [#permalink]

### Show Tags

24 Jan 2018, 05:40
KarolinaBambi wrote:
Hi!
I'd be incredibly greatful if you could provide me with a bit deeper explenation of the excercise below than it's in the Official Guide (pls see in the attachment).

"For any positive inteer n, the sum of the first n positive integers equals [n(n+1)][/2] . What is the sum of all the even integers between 99 and 301?"
a) 10,100
b) 20,200
c) 22,650
d) 40,200
e) 45,150

Why exactly does one have to use the sum of the 150 even integers and the substract the sum of the 49?

This question is discussed here: https://gmatclub.com/forum/for-any-posi ... 27817.html

In case of any further questions please post there.
_________________
Math Expert
Joined: 02 Sep 2009
Posts: 52390
Re: Algebra - summing up using Sigma notation  [#permalink]

### Show Tags

24 Jan 2018, 07:08
KarolinaBambi wrote:
Hi!
I'd be incredibly greatful if you could provide me with a bit deeper explenation of the excercise below than it's in the Official Guide (pls see in the attachment).

"For any positive inteer n, the sum of the first n positive integers equals [n(n+1)][/2] . What is the sum of all the even integers between 99 and 301?"
a) 10,100
b) 20,200
c) 22,650
d) 40,200
e) 45,150

Why exactly does one have to use the sum of the 150 even integers and the substract the sum of the 49?

--== Message from the GMAT Club Team ==--

THERE IS LIKELY A BETTER DISCUSSION OF THIS EXACT QUESTION.
This discussion does not meet community quality standards. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.

_________________
Re: Algebra - summing up using Sigma notation &nbs [#permalink] 24 Jan 2018, 07:08
Display posts from previous: Sort by