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 Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

If a equals the sum of the even integers from 2 to 20, inclusive, and [#permalink]

Show Tags

04 Apr 2007, 19:30

11

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

25% (medium)

Question Stats:

70% (01:00) correct 30% (01:03) wrong based on 732 sessions

HideShow timer Statistics

If a equals the sum of the even integers from 2 to 20, inclusive, and b equals the sum of the odd integers from 1 to 19, inclusive, what is the value of a - b ?

Re: If a equals the sum of the even integers from 2 to 20, inclusive, and [#permalink]

Show Tags

04 Apr 2007, 19:36

3

This post received KUDOS

3

This post was BOOKMARKED

The sum is 10.

The fastest way is to notice that since we're taking a-b, all we are going to end up with is addings ten '1' since each even number is one larger than the odd.

Re: If a equals the sum of the even integers from 2 to 20, inclusive, and [#permalink]

Show Tags

03 Nov 2014, 21:23

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

If a equals the sum of the even integers from 2 to 20, inclusive, and b equals the sum of the odd integers from 1 to 19, inclusive, what is the value of a - b ?

A. 1 B. 10 C. 19 D. 20 E. 21

Hi, Another way.. Without getting into the sum etc, the answer can be found easily... 2-20 contains 10 integers and similarily 1-19 also has 10 integers.. smallest integer of a is greater by 1 than the corresponding integer of b.. and these is same for all 10 integers.. so a-b=1*10=10
_________________

Re: If a equals the sum of the even integers from 2 to 20, inclusive, and [#permalink]

Show Tags

07 Feb 2016, 02:18

chetan2u wrote:

faifai0714 wrote:

If a equals the sum of the even integers from 2 to 20, inclusive, and b equals the sum of the odd integers from 1 to 19, inclusive, what is the value of a - b ?

A. 1 B. 10 C. 19 D. 20 E. 21

Hi, Another way.. Without getting into the sum etc, the answer can be found easily... 2-20 contains 10 integers and similarily 1-19 also has 10 integers.. smallest integer of a is greater by 1 than the corresponding integer of b.. and these is same for all 10 integers.. so a-b=1*10=10

how to count number of odd integers from 1 to n inclusive? Please advise
_________________

"When you want to succeed as bad as you want to breathe, then you’ll be successful.” - Eric Thomas

If a equals the sum of the even integers from 2 to 20, inclusive, and b equals the sum of the odd integers from 1 to 19, inclusive, what is the value of a - b ?

A. 1 B. 10 C. 19 D. 20 E. 21

Hi, Another way.. Without getting into the sum etc, the answer can be found easily... 2-20 contains 10 integers and similarily 1-19 also has 10 integers.. smallest integer of a is greater by 1 than the corresponding integer of b.. and these is same for all 10 integers.. so a-b=1*10=10

how to count number of odd integers from 1 to n inclusive? Please advise

Hi, If n is odd, add 1to it and divide by 2... If n is even, straight way divide by 2... In this example, n is 19.. Add one,so 20.. 20/2=10..

smartguy595, at times it might be that you are given some integer in between to another integer ahead.. example, it may not be 1 to n, but n to x.. few points to note in that scenario..

1) both x and n are even total integers will be (x-n)+1... even will be 1 more than odd.. even= (x-n)/2+1 and odd=(x-n)/2..

2) x is even and n is odd.. total integers = x-n +1.. even will be equal to odd.. even= odd={(x-n)+1}/2 ..

3)x is odd and n is even.. total integers = x-n +1.. even will be equal to odd.. even= odd={(x-n)+1}/2 ..

4) both x and n are odd total integers will be (x-n)+1... odd will be 1 more than even.. odd= (x-n)/2+1 and even=(x-n)/2..

Your query on 1 to 19 will fall under 3) and 4) above.. hope this helps..
_________________

Re: If a equals the sum of the even integers from 2 to 20, inclusive, and [#permalink]

Show Tags

28 Aug 2016, 23:33

1

This post received KUDOS

faifai0714 wrote:

If a equals the sum of the even integers from 2 to 20, inclusive, and b equals the sum of the odd integers from 1 to 19, inclusive, what is the value of a - b ?

A. 1 B. 10 C. 19 D. 20 E. 21

Solution :

a = Sum of all even integers between 2 to 20 Theory : Sum of n even integers = n(n+1) Therefore a = n^2+n

b = sum of all odd integers between 1 to 19 Theory : Sum of n odd integers = n^2

Therefore a-b = n^2+n-n^2 = n

Here n = no of even integers between 2 to 20 = no of odd integers between 1 to 19 = 10

Re: If a equals the sum of the even integers from 2 to 20, inclusive, and [#permalink]

Show Tags

29 Aug 2016, 00:26

faifai0714 wrote:

If a equals the sum of the even integers from 2 to 20, inclusive, and b equals the sum of the odd integers from 1 to 19, inclusive, what is the value of a - b ?

A. 1 B. 10 C. 19 D. 20 E. 21

Option B sum of even integers = 10*22/2= 110 sum of odd integers = 10*20/2 =100 a - b= 110-100 =10
_________________

Re: If a equals the sum of the even integers from 2 to 20, inclusive, and [#permalink]

Show Tags

01 Sep 2017, 23:21

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

Re: If a equals the sum of the even integers from 2 to 20, inclusive, and [#permalink]

Show Tags

02 Sep 2017, 04:14

We can list numbers as 2 4 6 .....20 and odd numbers 1 3 5 ....19 There are a total of 10 even 10 odd numbers so if we subtract each corresponding odd number from even numbers we will get 1 so total will be 10
_________________

We are more often frightened than hurt; and we suffer more from imagination than from reality