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If x is equal to the sum of even integers from 40 to 60, [#permalink]
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07 Oct 2005, 07:21
If x is equal to the sum of even integers from 40 to 60, inclusive, and y is the number of even integers from 40 to 60, inclusive, what is the value of y?
(A) 550
(B) 551
(C) 560
(D) 561
(E) 572
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2+4+6+8= 20 x2
40 + 40 + 40 + 40+ 40 = 200
50 + 50 + 50 + 50 + 50 = 250
60
40+ 200+ 250+ 60= 550
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Re: Calculating Integers [#permalink]
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07 Oct 2005, 07:37
Ã©tudiant wrote: If x is equal to the sum of even integers from 40 to 60, inclusive, and y is the number of even integers from 40 to 60, inclusive, what is the value of y?
(A) 550 (B) 551 (C) 560 (D) 561 (E) 572
Please explain your answer.
When you're writing ... y is the number... I suppose you're meaning the SUM, right!?
If y would be the sum of all even integers, it would be according to Gauss:
y = (First summand + last summand) / (Half of the number of summands)
= (40 + 60) / (11/2) = 550 > A



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Re: Calculating Integers [#permalink]
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07 Oct 2005, 09:29
lazy_k wrote: When you're writing ... y is the number... I suppose you're meaning the SUM, right!?
If y would be the sum of all even integers, it would be according to Gauss:
y = (First summand + last summand) / (Half of the number of summands) = (40 + 60) / (11/2) = 550 > A
You reminded me the school story of our friend Gauss where he had to sum 1100



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Re: Calculating Integers [#permalink]
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07 Oct 2005, 12:43
Ã©tudiant wrote: If x is equal to the sum of even integers from 40 to 60, inclusive, and y is the number of even integers from 40 to 60, inclusive, what is the value of y?
(A) 550 (B) 551 (C) 560 (D) 561 (E) 572
Please explain your answer.
I agree with ranga41... is there something missing in this question or a typo?
If its sum... lazy_k is on the money with the solution!
we are asked to find the "number of even integers" or y between 40 and 60 which would be 11... ??
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Re: Calculating Integers [#permalink]
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07 Oct 2005, 19:23
vikramm wrote: Ã©tudiant wrote: If x is equal to the sum of even integers from 40 to 60, inclusive, and y is the number of even integers from 40 to 60, inclusive, what is the value of y?
(A) 550 (B) 551 (C) 560 (D) 561 (E) 572
Please explain your answer. I agree with ranga41... is there something missing in this question or a typo? If its sum... lazy_k is on the money with the solution! we are asked to find the "number of even integers" or y between 40 and 60 which would be 11... ??
It is a typo. It suppose to be "what is the value of x + y?" Sorry.
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am getting D..now
whats the OA



Intern
Joined: 03 Feb 2005
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OA is D
Please explain this answer. Thanks
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Re: Calculating Integers [#permalink]
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10 Oct 2005, 05:05
Ã©tudiant wrote: vikramm wrote: Ã©tudiant wrote: If x is equal to the sum of even integers from 40 to 60, inclusive, and y is the number of even integers from 40 to 60, inclusive, what is the value of y?
(A) 550 (B) 551 (C) 560 (D) 561 (E) 572
Please explain your answer. I agree with ranga41... is there something missing in this question or a typo? If its sum... lazy_k is on the money with the solution! we are asked to find the "number of even integers" or y between 40 and 60 which would be 11... ?? It is a typo. It suppose to be "what is the value of x + y?" Sorry.
This is an AP with the first tem as 40 and last term as 60 and there are 11 terms between 40 and 60 with a difference of 2, so sum of these terms is
s = (n/2) (a + l) = (11/2) (40 + 60) = 550 = X
Y = number of terms = 11
so the answer is 561



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The sum of all the even numbers between 40 and 60, both included, is 550. The number of even numbers is 11. Therefore, x+y is 561 and the correct answer is D.



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Re: If x is equal to the sum of even integers from 40 to 60, [#permalink]
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12 Nov 2017, 05:31
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Re: If x is equal to the sum of even integers from 40 to 60,
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