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MasterGMAT12
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If x is equal to the sum of the integers from 30 to 50, incl 19 Dec 2010, 16:14
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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
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E
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Bunuel
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If x is equal to the sum of the integers from 30 to 50, incl 19 Dec 2010, 16:31
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MasterGMAT12
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 \(y=\frac{50-30}{2}+1=11\) (check this: totally-basic-94862.html);

x+y=840+11=851.

Answer: E.


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If x is equal to the sum of the integers from 30 to 50, incl Updated on: 23 Jul 2018, 00:14
Originally posted by nimc2012 on 08 Feb 2012, 15:31.
Last edited by Bunuel on 23 Jul 2018, 00:14, edited 4 times in total.
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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 = ????
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If x is equal to the sum of the integers from 30 to 50, incl 08 Feb 2012, 15:37
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nimc2012
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 \(y=\frac{50-30}{2}+1=11\) (check this: totally-basic-94862.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.
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If x is equal to the sum of the integers from 30 to 50, incl 10 Feb 2013, 08:58
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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!
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If x is equal to the sum of the integers from 30 to 50, incl 11 Feb 2013, 20:09
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Since the integers from 30-50 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 30-50 = y. Therefore, x+y = 851. Answer: E
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If x is equal to the sum of the integers from 30 to 50, incl 28 Aug 2014, 09:54
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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 :)
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If x is equal to the sum of the integers from 30 to 50, incl 18 Feb 2015, 01:45
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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 (50-30+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 (((50-30)/2)+1) with common difference 2)
Y=11

X+Y = 840+11 = 851

E
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If x is equal to the sum of the integers from 30 to 50, incl 16 Dec 2015, 03:36
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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
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If x is equal to the sum of the integers from 30 to 50, incl 16 Dec 2015, 09:13
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Bunuel
MasterGMAT12
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 \(y=\frac{50-30}{2}+1=11\) (check this: totally-basic-94862.html);

x+y=840+11=851.

Answer: E.


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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.
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If x is equal to the sum of the integers from 30 to 50, incl 17 Dec 2015, 09:43
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Bunuel
MasterGMAT12
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 \(y=\frac{50-30}{2}+1=11\) (check this: totally-basic-94862.html);

x+y=840+11=851.

Answer: E.


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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.
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If x is equal to the sum of the integers from 30 to 50, incl 18 Mar 2017, 10:37
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21*(30+50)/2=840

(50-30)/2=10+1=11
Answer is 851 or E
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If x is equal to the sum of the integers from 30 to 50, incl 22 Sep 2019, 13:18
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nimc2012
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 = ????


you have add no. of terms that is 11 hence x+y = 840+11 = 851

you halfway approach was good though.
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If x is equal to the sum of the integers from 30 to 50, incl 26 Jul 2022, 08:07
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