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the sum of the first 23 terms of the series
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31 Mar 2021, 02:24
31 Mar 2021, 02:24
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86% (01:10) correct
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2 + 4 + 6 + 8 + . . . + 98 + 100
A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
Kudos for the right answer and explanation
Question part of the project GRE Quantitative Reasoning Daily Challenge - (2021) EDITION
GRE - Math Book
Quantity A |
Quantity B |
the sum of the first 23 terms of the series |
550 |
A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
Kudos for the right answer and explanation
Question part of the project GRE Quantitative Reasoning Daily Challenge - (2021) EDITION
GRE - Math Book
Re: the sum of the first 23 terms of the series
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31 Mar 2021, 07:19
31 Mar 2021, 07:19
1
2 + 4 + 6 + 8 + . . . + 98 + 100
Qt A
First 23 terms will be up to 46
Sum = n (n + 1) = 23 * 24 = 552
Qt A > Qt B
Answer A
Qt A
First 23 terms will be up to 46
Sum = n (n + 1) = 23 * 24 = 552
Qt A > Qt B
Answer A
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Re: the sum of the first 23 terms of the series
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31 Mar 2021, 07:23
31 Mar 2021, 07:23
Carcass wrote:
2 + 4 + 6 + 8 + . . . + 98 + 100
A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
Quantity A |
Quantity B |
the sum of the first 23 terms of the series |
550 |
A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
It's an A.P with \(a = 2\) and \(d = 2\)
\(S_{23} = \frac{23}{2} [2(2) + (23-1)2]\)
\(S_{23} = 552\)
Col. A: \(552\)
Col. B: \(550\)
Hence, option A
Another Approach:
Sum of \(n\) consecutive even integers is given by \(n(n + 1)\)
So, \(S_{23} = 23(24) = 552\)
