January 19, 2019 January 19, 2019 07:00 AM PST 09:00 AM PST Aiming to score 760+? Attend this FREE session to learn how to Define your GMAT Strategy, Create your Study Plan and Master the Core Skills to excel on the GMAT. January 20, 2019 January 20, 2019 07:00 AM PST 07:00 AM PST Get personalized insights on how to achieve your Target Quant Score.
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, 15:14
Question Stats:
73% (01:52) correct 27% (02:22) wrong based on 265 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
Official Answer and Stats are available only to registered users. Register/ Login.
_________________
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: 52285

Re: Number Properties Question
[#permalink]
Show Tags
19 Dec 2010, 15:31



Intern
Joined: 18 Jan 2012
Posts: 21

If x is equal to the sum of the integers from 30 to 50, incl
[#permalink]
Show Tags
Updated on: 22 Jul 2018, 23:14
I started solving like this .....
Sum of integers = (Mean x No of Terms)
So for X  {30 to 50} , No. of terms = 21, Mean = 50+30 / 2 = 40 So Sum of X = No of terms x Mean = 21 x 40 = 840  Now for Y  {30, 32,34,36,38,40,42,44,46,48,50} Now since these have already been added before.....what am i supposed to do?......i am lost here..
Sum = x + y = ????
Originally posted by nimc2012 on 08 Feb 2012, 14:31.
Last edited by Bunuel on 22 Jul 2018, 23:14, edited 4 times in total.
Edited the question



Math Expert
Joined: 02 Sep 2009
Posts: 52285

Re: Consecutive Numbers (Number Properties)
[#permalink]
Show Tags
08 Feb 2012, 14:37
nimc2012 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

I started solving like this .....
Sum of integers = (Mean x No of Terms)
So for X  {30 to 50} , No. of terms = 21, Mean = 50+30 / 2 = 40 So Sum of X = No of terms x Mean = 21 x 40 = 840  Now for Y  {30, 32,34,36,38,40,42,44,46,48,50} Now since these have already been added before.....what am i supposed to do?......i am lost here..
Sum = x + y = ???? The sum of the integers from 30 to 50, inclusive 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 \(y=\frac{5030}{2}+1=11\) (check this: totallybasic94862.html); x+y=840+11=851. Answer: E. As for your question: x and y are two different numbers: x is a sum of the integers from 30 to 50, inclusive and y is the number of EVEN integers from 30 to 50, inclusive. Hope it's clear.
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



Manager
Joined: 16 Feb 2012
Posts: 174
Concentration: Finance, Economics

Re: If x is equal to the sum of the integers from 30 to 50
[#permalink]
Show Tags
10 Feb 2013, 07:58
The correct answer to this question is E not D. You put D as the correct answer, so you could change it to E. It is confusing at first look. Thanks!
_________________
Kudos if you like the post!
Failing to plan is planning to fail.



Manager
Joined: 18 Oct 2011
Posts: 86
Location: United States
Concentration: Entrepreneurship, Marketing
GMAT Date: 01302013
GPA: 3.3

Re: If x is equal to the sum of the integers from 30 to 50
[#permalink]
Show Tags
11 Feb 2013, 19:09
Since the integers from 3050 are consecutive we can use the "median x # of terms formula" to determine x. There are 21 terms and the median is 40. This gives a total of 21x40 = 840. There are 11 even integers from 3050 = y. Therefore, x+y = 851. Answer: E



NUS Thread Master
Affiliations: Oracle certified java programmer , adobe certified developer
Joined: 14 Jul 2013
Posts: 60
GMAT Date: 02122015
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, 08:54
I will use AP: Sum = n/2[2a+(n1)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



Intern
Joined: 15 Jan 2015
Posts: 23

Re: If x is equal to the sum of the integers from 30 to 50
[#permalink]
Show Tags
18 Feb 2015, 00:45
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
For X, Series is  30,31,32,33,.......,48,49,50 (21 terms (5030+1) with common difference 1) Sum = (21/2)*((2*30)+(20)) = 21*40 = 840
For Y, Series is  30,32,34,....48,50 (11 terms (((5030)/2)+1) with common difference 2) Y=11
X+Y = 840+11 = 851
E



Director
Joined: 23 Jan 2013
Posts: 559

If x is equal to the sum of the integers from 30 to 50, incl
[#permalink]
Show Tags
16 Dec 2015, 02:36
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: 38

Re: If x is equal to the sum of the integers from 30 to 50, incl
[#permalink]
Show Tags
16 Dec 2015, 08:13
Bunuel wrote: MasterGMAT12 wrote: Please help with the approach for the below question:
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 \(y=\frac{5030}{2}+1=11\) (check this: totallybasic94862.html); x+y=840+11=851. Answer: E. 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: 52285

Re: If x is equal to the sum of the integers from 30 to 50, incl
[#permalink]
Show Tags
17 Dec 2015, 08:43
sharma123 wrote: Bunuel wrote: MasterGMAT12 wrote: Please help with the approach for the below question:
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 \(y=\frac{5030}{2}+1=11\) (check this: totallybasic94862.html); x+y=840+11=851. Answer: E. 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.
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



Manager
Joined: 03 Jan 2017
Posts: 150

Re: If x is equal to the sum of the integers from 30 to 50, incl
[#permalink]
Show Tags
18 Mar 2017, 09:37
21*(30+50)/2=840
(5030)/2=10+1=11 Answer is 851 or E




Re: If x is equal to the sum of the integers from 30 to 50, incl &nbs
[#permalink]
18 Mar 2017, 09:37






