Nov 28 08:00 PM PST  09:00 PM PST Magoosh is excited to offer you a free GRE practice test with video answers and explanations. If you’re thinking about taking the GRE or want to see how effective your GRE test prep has been, pinpoint your strengths and weaknesses with this quiz! Nov 30 08:00 PM PST  09:00 PM PST Take 20% off the plan of your choice, now through midnight on 11/30 Dec 02 07:30 AM PST  08:30 AM PST This webinar will focus on evaluating reading comprehension questions on the GRE and GMAT. This 60 minute class will be a mix of "presentation" and Q&A where students can get specific questions answered. Dec 04 10:00 PM PST  11:00 PM PST Regardless of whether you choose to study with Greenlight Test Prep, I believe you'll benefit from my many free resources. Dec 07 08:00 PM PST  09:00 PM PST This admissions guide will help you plan your best route to a PhD by helping you choose the best programs your goals, secure strong letters of recommendation, strengthen your candidacy, and apply successfully.
Author 
Message 
TAGS:


Senior Manager
Joined: 20 May 2014
Posts: 283
Followers: 24
Kudos [?]:
63
[0], given: 220

The sum of the multiples of 4 less than 100 or The sum of [#permalink]
22 Oct 2017, 06:14
Question Stats:
73% (01:02) correct
26% (01:05) wrong based on 104 sessions
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.




Director
Joined: 03 Sep 2017
Posts: 518
Followers: 2
Kudos [?]:
440
[3]
, given: 66

Re: The sum of the multiples of 4 less than 100 or The sum of [#permalink]
22 Oct 2017, 08:48
3
This post received KUDOS
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 \(\frac{1004}{4}+1 = 25\), while for column B we get \(\frac{1005}{5}+1 = 20\).
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!



Intern
Joined: 15 May 2018
Posts: 38
Followers: 0
Kudos [?]:
6
[0], given: 1

Re: The sum of the multiples of 4 less than 100 or The sum of [#permalink]
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



Intern
Joined: 04 May 2017
Posts: 36
Followers: 0
Kudos [?]:
29
[1]
, given: 6

Re: The sum of the multiples of 4 less than 100 or The sum of [#permalink]
10 Jul 2018, 08:19
1
This post received KUDOS
Sum of multiples of 4 = 4(1+2+..+25)=4*(25+1)*25/2=50*26 Sum of multiples of 5 = 5(1+2+..+20)=5*(1+20)*20/2=50*21 > QA > QB > A.
_________________
Do not pray for an easy life, pray for the strength to endure a difficult one  Bruce Lee



Manager
Joined: 27 Feb 2017
Posts: 188
Followers: 1
Kudos [?]:
78
[2]
, given: 15

Re: The sum of the multiples of 4 less than 100 or The sum of [#permalink]
05 Aug 2018, 15:33
2
This post received KUDOS
IlCreatore wrote: 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 \(\frac{1004}{4}+1 = 25\), while for column B we get \(\frac{1005}{5}+1 = 20\).
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! Hi, for step 1, is there a simplified formula that is easier to remember for exam? Also, it says less that 100, so shouldnt we consider multiples less than 100? Like is 100 still included? And thanks for the explanation btw



Intern
Joined: 06 Jul 2018
Posts: 29
Followers: 0
Kudos [?]:
1
[0], given: 5

Re: The sum of the multiples of 4 less than 100 or The sum of [#permalink]
09 Aug 2018, 00:53
it should be given that multiples are of what kind...positive or negative,and inclusive or exclusive....



Retired Moderator
Joined: 07 Jun 2014
Posts: 4803
WE: Business Development (Energy and Utilities)
Followers: 175
Kudos [?]:
3034
[0], given: 394

Re: The sum of the multiples of 4 less than 100 or The sum of [#permalink]
09 Aug 2018, 05:19
ragini123 wrote: it should be given that multiples are of what kind...positive or negative,and inclusive or exclusive.... Multiples are always considered as positive unless explicitly mentioned. Less than 100 means that 100 should not be considered for calculation in this case.
_________________
Sandy If you found this post useful, please let me know by pressing the Kudos Button
Try our free Online GRE Test



VP
Joined: 20 Apr 2016
Posts: 1302
WE: Engineering (Energy and Utilities)
Followers: 22
Kudos [?]:
1340
[2]
, given: 251

Re: The sum of the multiples of 4 less than 100 or The sum of [#permalink]
17 Apr 2019, 19:21
2
This post received KUDOS
IlCreatore wrote: 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 \(\frac{1004}{4}+1 = 25\), while for column B we get \(\frac{1005}{5}+1 = 20\).
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! I doubt the above explanation, kindly provide some feed back. As we need to find the multiples of 4 & 5 less than 100, i.e. 100 exclusiveQTY A :: since the number has to be less than 100 The number of terms = \(\frac{964}{4}+1 = 24\) ( last multiple of 4, less than 100  first multiple of 4 ) The average = \(\frac{{99 + 1}}{2} = 50\) Hence the multiples of 4 less than 100 = 50 * 24 QTY B:: The number of terms = \(\frac{955}{5}+1 = 19\) The average = \(\frac{{99 + 1}}{2} = 50\) Hence the multiples of 5 less than 100 = 50 * 19 Therefore QTY A > QTY B
_________________
If you found this post useful, please let me know by pressing the Kudos Button
Rules for Posting
Got 20 Kudos? You can get Free GRE Prep Club Tests
GRE Prep Club Members of the Month:TOP 10 members of the month with highest kudos receive access to 3 months GRE Prep Club tests



Intern
Joined: 27 Jun 2019
Posts: 40
Followers: 0
Kudos [?]:
9
[0], given: 3

Re: The sum of the multiples of 4 less than 100 or The sum of [#permalink]
27 Aug 2019, 00:18
pranab01 wrote: IlCreatore wrote: 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 \(\frac{1004}{4}+1 = 25\), while for column B we get \(\frac{1005}{5}+1 = 20\).
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! I doubt the above explanation, kindly provide some feed back. As we need to find the multiples of 4 & 5 less than 100, i.e. 100 exclusiveQTY A :: since the number has to be less than 100 The number of terms = \(\frac{964}{4}+1 = 24\) ( last multiple of 4, less than 100  first multiple of 4 ) The average = \(\frac{{99 + 1}}{2} = 50\) Hence the multiples of 4 less than 100 = 50 * 24 QTY B:: The number of terms = \(\frac{955}{5}+1 = 19\) The average = \(\frac{{99 + 1}}{2} = 50\) Hence the multiples of 5 less than 100 = 50 * 19 Therefore QTY A > QTY B I got the same!



Intern
Joined: 11 Aug 2020
Posts: 1
Followers: 0
Kudos [?]:
1
[1]
, given: 0

Re: The sum of the multiples of 4 less than 100 or The sum of [#permalink]
11 Aug 2020, 12:08
1
This post received KUDOS
We know that: Sum of integers from 1 to n is (n)(n+1)/2
Quantity A = Sum of multiples of 4 till 100 = 4 + 8 + 12 ...... 96 + 100 = 4*(1 + 2 + 3 ...... 24 + 25) = 4*(25)(25+1)/2 = 4*25*13 (divided 26 by 2) = 1300
Quantity B = Sum of multiples of 5 till 100 = 5 + 10 + 15 ...... 95 + 100 = 5*(1 + 2 + 3 ...... 19 + 20) = 5*(20)(20+1)/2 = 5*10*21 (divided 20 by 2) = 1050
So, A > B



Intern
Joined: 07 Sep 2020
Posts: 15
Followers: 0
Kudos [?]:
1
[0], given: 0

Re: The sum of the multiples of 4 less than 100 or The sum of [#permalink]
07 Sep 2020, 07:40
but n/2[2a+(n1)d] is also valid? but why i am not getting right answer?




Re: The sum of the multiples of 4 less than 100 or The sum of
[#permalink]
07 Sep 2020, 07:40





