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

 It is currently 18 Jun 2018, 23:38

### 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 June
Open Detailed Calendar

# If x is equal to the sum of the integers from 30 to 50, incl

Author Message
TAGS:

### Hide Tags

Intern
Joined: 12 Dec 2010
Posts: 13
Schools: Wharton, Columbia, Booth, NYU
If x is equal to the sum of the integers from 30 to 50, incl [#permalink]

### Show Tags

19 Dec 2010, 16:14
1
5
00:00

Difficulty:

35% (medium)

Question Stats:

71% (01:29) correct 29% (02:02) wrong based on 298 sessions

### HideShow timer Statistics

If x is equal to the sum of the integers from 30 to 50, inclusive, and y is the number of even integers from 30 to 50, inclusive, what is the value of x + y ?

(A) 810
(B) 811
(C) 830
(D) 850
(E) 851

_________________

Practice, More Practice, Still More Practice... THE only way to succeed!!!
+1Kudos, if this helps with your preparation. Good luck!

Math Expert
Joined: 02 Sep 2009
Posts: 46146

### Show Tags

19 Dec 2010, 16:31
2
1
MasterGMAT12 wrote:

If x is equal to the sum of the integers from 30 to 50, inclusive, and y is the number of even integers from 30 to 50, inclusive, what is the value of x + y ?
(A) 810
(B) 811
(C) 830
(D) 850
(E) 851

The sum of the integers from 30 to 50 is $$x=\frac{first \ term+ last \ term}{2}*# \ of \ terms=\frac{30+50}{2}*21=40*21=840$$;

The number of even integers from 30 to 50 is $$y=\frac{50-30}{2}+1=11$$ (check this: totally-basic-94862.html);

x+y=840+11=851.

 ! Please post PS questions in the PS subforum: gmat-problem-solving-ps-140/Please post DS questions in the DS subforum: gmat-data-sufficiency-ds-141/No posting of PS/DS questions is allowed in the main Math forum.

_________________
Affiliations: Oracle certified java programmer , adobe certified developer
Joined: 14 Jul 2013
Posts: 96
GMAT Date: 02-12-2015
GPA: 3.87
WE: Programming (Telecommunications)
Re: If x is equal to the sum of the integers from 30 to 50, incl [#permalink]

### Show Tags

28 Aug 2014, 09:54
I will use AP:

Sum = n/2[2a+(n-1)d) = 21/2[2*30+20*1] = 840 = sum from 30- 50
Number of even terms from 30 -50 are 11.
so total = 240+11 =251
Hope this helps
_________________

IF IT IS TO BE , IT IS UP TO ME

Director
Joined: 23 Jan 2013
Posts: 597
Schools: Cambridge'16
If x is equal to the sum of the integers from 30 to 50, incl [#permalink]

### Show Tags

16 Dec 2015, 03:36
21 integers from 30 to 50 inclusive

so 11th integer is mean, it is 40

21*40=840

from 21 integers 11 ones is even

840+11=851

E
Intern
Joined: 29 Oct 2014
Posts: 40
Re: If x is equal to the sum of the integers from 30 to 50, incl [#permalink]

### Show Tags

16 Dec 2015, 09:13
Bunuel wrote:
MasterGMAT12 wrote:

If x is equal to the sum of the integers from 30 to 50, inclusive, and y is the number of even integers from 30 to 50, inclusive, what is the value of x + y ?
(A) 810
(B) 811
(C) 830
(D) 850
(E) 851

The sum of the integers from 30 to 50 is $$x=\frac{first \ term+ last \ term}{2}*# \ of \ terms=\frac{30+50}{2}*21=40*21=840$$;

The number of even integers from 30 to 50 is $$y=\frac{50-30}{2}+1=11$$ (check this: totally-basic-94862.html);

x+y=840+11=851.

 ! Please post PS questions in the PS subforum: gmat-problem-solving-ps-140/Please post DS questions in the DS subforum: gmat-data-sufficiency-ds-141/No posting of PS/DS questions is allowed in the main Math forum.

Hi Bunuel how do you calculate no. of terms(i.e 21). By counting or is there any method. Counting no. of terms in given range or no. of hours have always been a problem for me. i always count which consumes a lot of time.
Math Expert
Joined: 02 Sep 2009
Posts: 46146
Re: If x is equal to the sum of the integers from 30 to 50, incl [#permalink]

### Show Tags

17 Dec 2015, 09:43
sharma123 wrote:
Bunuel wrote:
MasterGMAT12 wrote:

If x is equal to the sum of the integers from 30 to 50, inclusive, and y is the number of even integers from 30 to 50, inclusive, what is the value of x + y ?
(A) 810
(B) 811
(C) 830
(D) 850
(E) 851

The sum of the integers from 30 to 50 is $$x=\frac{first \ term+ last \ term}{2}*# \ of \ terms=\frac{30+50}{2}*21=40*21=840$$;

The number of even integers from 30 to 50 is $$y=\frac{50-30}{2}+1=11$$ (check this: totally-basic-94862.html);

x+y=840+11=851.

 ! Please post PS questions in the PS subforum: gmat-problem-solving-ps-140/Please post DS questions in the DS subforum: gmat-data-sufficiency-ds-141/No posting of PS/DS questions is allowed in the main Math forum.

Hi Bunuel how do you calculate no. of terms(i.e 21). By counting or is there any method. Counting no. of terms in given range or no. of hours have always been a problem for me. i always count which consumes a lot of time.

How many integers are from x to y inclusive? y - x + 1.
For example, how many integers are from 2 to 7 inclusive? 7 - 2 + 1 = 6. Namely, 2, 3, 4, 5, 6 and 7.

How many integers are from x to y NOT inclusive? y - x - 1.
For example, how many integers are from 2 to 7 NOT inclusive? 7 - 2 - 1 = 4. Namely, 3, 4, 5, and 6.
_________________
Manager
Joined: 03 Jan 2017
Posts: 181
Re: If x is equal to the sum of the integers from 30 to 50, incl [#permalink]

### Show Tags

18 Mar 2017, 10:37
21*(30+50)/2=840

(50-30)/2=10+1=11
Re: If x is equal to the sum of the integers from 30 to 50, incl   [#permalink] 18 Mar 2017, 10:37
Display posts from previous: Sort by