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The sum of the multiples of 4 less than 100 or The sum of
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22 Oct 2017, 06:14
22 Oct 2017, 06:14
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Question Stats:
71% (01:11) correct
28% (01:02) wrong based on 166 sessions
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Quantity A |
Quantity B |
The sum of the multiples of 4 less than 100 |
The sum of the multiples of 5 less than 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 correct solution.
Re: The sum of the multiples of 4 less than 100 or The sum of
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22 Oct 2017, 08:48
22 Oct 2017, 08:48
4
We can proceed by steps:
1) number of elements in the two sets: we have to take the first and the last multiple, then compute last - first, divide by the number whose multiples are of interest and sum 1. In our case, in column A, we have \(\frac{100-4}{4}+1 = 25\), while for column B we get \(\frac{100-5}{5}+1 = 20\).
2) Compute the sum. The formula for the sum of an arithmetic progression is \(sum = \frac{n}{2}(first+last)\), where n is the number of elements in the progression and first and last are the first and the last elements. Thus, for column A, \(\frac{25}{2}(4+100) = 1300\), while column B equates \(\frac{20}{2}(5+100) = 1050\).
We conclude that A is greater!
1) number of elements in the two sets: we have to take the first and the last multiple, then compute last - first, divide by the number whose multiples are of interest and sum 1. In our case, in column A, we have \(\frac{100-4}{4}+1 = 25\), while for column B we get \(\frac{100-5}{5}+1 = 20\).
2) Compute the sum. The formula for the sum of an arithmetic progression is \(sum = \frac{n}{2}(first+last)\), where n is the number of elements in the progression and first and last are the first and the last elements. Thus, for column A, \(\frac{25}{2}(4+100) = 1300\), while column B equates \(\frac{20}{2}(5+100) = 1050\).
We conclude that A is greater!
Re: The sum of the multiples of 4 less than 100 or The sum of
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09 Jul 2018, 18:48
09 Jul 2018, 18:48
Bunuel wrote:
Quantity A |
Quantity B |
The sum of the multiples of 4 less than 100 |
The sum of the multiples of 5 less than 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 correct solution.
My Answer is A
