Author 
Message 
TAGS:

Hide Tags

Intern
Joined: 09 Feb 2012
Posts: 47

In last examination Roger scored marks in each of 5 subjects [#permalink]
Show Tags
04 Mar 2012, 07:34
3
This post received KUDOS
6
This post was BOOKMARKED
Question Stats:
69% (08:03) correct
31% (02:06) wrong based on 259 sessions
HideShow timer Statistics
In last examination Roger scored marks in each of 5 subjects in the following ratio 4:5:6:7:8 and got an overall score of 72%. If 50% of the maximum marks is passing and the maximum marks of each subject is the same, in how many subjects did Roger fail? A. 1 B. 2 C. 3 D. 4 E. 5 Many thanks. Have a great Sunday!
Official Answer and Stats are available only to registered users. Register/ Login.
Last edited by Bunuel on 04 Mar 2012, 08:08, edited 1 time in total.
Edited the question and moved to PS subforum



Math Expert
Joined: 02 Sep 2009
Posts: 39713

Re: Ratio question [#permalink]
Show Tags
04 Mar 2012, 08:07
4
This post received KUDOS
Expert's post
4
This post was BOOKMARKED
In last examination Roger scored marks in each of 5 subjects in the following ratio 4:5:6:7:8 and got an overall score of 72%. If 50% of the maximum marks is passing and the maximum marks of each subject is the same, in how many subjects did Roger fail?A. 1 B. 2 C. 3 D. 4 E. 5 Given: A:B:C:D:E=4x:5x:6x:7x:8x, for some multiple x. Assume the maximum marks of each subject to be y, so the the maximum marks of ALL 5 subjects will be 5y. So, we have that \(4x+5x+6x+7x+8x=\frac{72}{100}*5y\) > \(30x=\frac{72*5}{100}*y\) > \(x=\frac{12}{100}*y\). \(4x=\frac{48}{100}*y\) and \(5x=\frac{60}{100}*y\), so in subject A Roger scored 48% (less than 50%) and in subject B 60% (more than 50%). Obviously in all other subjects Rogers scores will be higher than 50%. Roger failed in only one subject A. Answer: A. P.S. Please post PS questions in the PS subforum: gmatproblemsolvingps140/ and DS questions in the DS subforum: gmatdatasufficiencyds141/
No posting of PS/DS questions is allowed in the main Math forum.
_________________
New to the Math Forum? Please read this: All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



Intern
Joined: 09 Feb 2012
Posts: 47

Re: In last examination Roger scored marks in each of 5 subjects [#permalink]
Show Tags
04 Mar 2012, 08:17
Many thanks!!!
But I dont really get the step, to multiply with 5y
Could you please explain it to me.
Thanks!



Math Expert
Joined: 02 Sep 2009
Posts: 39713

Re: In last examination Roger scored marks in each of 5 subjects [#permalink]
Show Tags
04 Mar 2012, 08:41



Senior Manager
Joined: 18 Sep 2009
Posts: 355

Re: In last examination Roger scored marks in each of 5 subjects [#permalink]
Show Tags
05 Mar 2012, 11:41
Hi bunnel
can you suggest any material for ratio and proportions. I have completed ratio and proportions in manhattan word translations, but still i need some extra practice
Thanks



Math Expert
Joined: 02 Sep 2009
Posts: 39713

Re: In last examination Roger scored marks in each of 5 subjects [#permalink]
Show Tags
05 Mar 2012, 11:59



Intern
Joined: 08 Mar 2012
Posts: 4

Re: In last examination Roger scored marks in each of 5 subjects [#permalink]
Show Tags
20 Mar 2012, 21:37
4
This post received KUDOS
I did this by picking numbers. Say the max mark in each subject is 100. Then I can directly know that Roger scored 40,50,60,70,80. Since passing mark is 50% of max mark => passing mark = 50. Thus Roger failed in only 1 subject, where he scored 40.
Answer A.



Manager
Joined: 07 Dec 2011
Posts: 157
Location: India

Re: In last examination Roger scored marks in each of 5 subjects [#permalink]
Show Tags
23 Mar 2012, 04:48
2
This post received KUDOS
took x as a percentage of score in an exam
(4x+5x+6x+7x+8x)5 =72 = avg percentage 6x=72 x = 12
therefore marks are 48%, 60% and so on and only the one value 48% is below the passing threshold of 50%. Hence, A.



Senior Manager
Joined: 13 Mar 2012
Posts: 358
Concentration: Operations, Strategy

Re: In last examination Roger scored marks in each of 5 subjects [#permalink]
Show Tags
23 Mar 2012, 06:06
NYC5648 wrote: In last examination Roger scored marks in each of 5 subjects in the following ratio 4:5:6:7:8 and got an overall score of 72%. If 50% of the maximum marks is passing and the maximum marks of each subject is the same, in how many subjects did Roger fail?
A. 1 B. 2 C. 3 D. 4 E. 5
Many thanks. Have a great Sunday! LET MAX MARKS BE Y then (4+5+6+7+8)x=0.72*5y => 30x=3.6y => x=36y/300=3y/25 hence 4x= 4*3y/25=12y/25> fail 5x> pass as all other scores are greater than 5x hence he passed in all hence failed in 1 subject option A
_________________
Practice Practice and practice...!!
If my reply /analysis is helpful>please press KUDOS If there's a loophole in my analysis> suggest measures to make it airtight.



Math Expert
Joined: 02 Sep 2009
Posts: 39713

Re: In last examination Roger scored marks in each of 5 subjects [#permalink]
Show Tags
24 Jun 2013, 04:04



Director
Joined: 25 Apr 2012
Posts: 728
Location: India
GPA: 3.21
WE: Business Development (Other)

Re: In last examination Roger scored marks in each of 5 subjects [#permalink]
Show Tags
25 Jun 2013, 12:01
1
This post received KUDOS
1
This post was BOOKMARKED
NYC5648 wrote: In last examination Roger scored marks in each of 5 subjects in the following ratio 4:5:6:7:8 and got an overall score of 72%. If 50% of the maximum marks is passing and the maximum marks of each subject is the same, in how many subjects did Roger fail?
A. 1 B. 2 C. 3 D. 4 E. 5
Many thanks. Have a great Sunday! For ratio and proportion questions, We can always check at first for plugging in values. Let us assume that for each exam the max score is 100. So total max score in 5 exams is 500 where as Roger scored 72% of 500 which is 360 360 is total marks scored by Roger which is nothing but some of sum of his scores in all subjects so we have 4a+5a+6a+7a+8a = 360 where "a" is any positive integer, solving for "a", we get 30a= 360 > a=12 4a= 48 < 50 and in rest all exams he passed so ans should be A
_________________
“If you can't fly then run, if you can't run then walk, if you can't walk then crawl, but whatever you do you have to keep moving forward.”



Current Student
Joined: 06 Sep 2013
Posts: 1997
Concentration: Finance

Re: In last examination Roger scored marks in each of 5 subjects [#permalink]
Show Tags
03 Jan 2014, 08:03
NYC5648 wrote: In last examination Roger scored marks in each of 5 subjects in the following ratio 4:5:6:7:8 and got an overall score of 72%. If 50% of the maximum marks is passing and the maximum marks of each subject is the same, in how many subjects did Roger fail?
A. 1 B. 2 C. 3 D. 4 E. 5
Many thanks. Have a great Sunday! Total sum of scores is 30x Total sum of scores is also 720 720/30 = 12 = x So then, we can start with the first and it will give 48, fail Next is obviously 60 pass, so only 1 fail Hence A Hope it helps! Cheers J



Intern
Joined: 05 Dec 2013
Posts: 16

Re: Ratio question [#permalink]
Show Tags
08 Mar 2014, 08:57
Bunuel wrote: In last examination Roger scored marks in each of 5 subjects in the following ratio 4:5:6:7:8 and got an overall score of 72%. If 50% of the maximum marks is passing and the maximum marks of each subject is the same, in how many subjects did Roger fail?A. 1 B. 2 C. 3 D. 4 E. 5 Given: A:B:C:D:E=4x:5x:6x:7x:8x, for some multiple x. Assume the maximum marks of each subject to be y, so the the maximum marks of ALL 5 subjects will be 5y. So, we have that \(4x+5x+6x+7x+8x=\frac{72}{100}*5y\) > \(30x=\frac{72*5}{100}*y\) > \(x=\frac{12}{100}*y\). \(4x=\frac{48}{100}*y\) and \(5x=\frac{60}{100}*y\), so in subject A Roger scored 48% (less than 50%) and in subject B 60% (more than 50%). Obviously in all other subjects Rogers scores will be higher than 50%.Roger failed in only one subject A. Answer: A. P.S. Please post PS questions in the PS subforum: gmatproblemsolvingps140/ and DS questions in the DS subforum: gmatdatasufficiencyds141/
No posting of PS/DS questions is allowed in the main Math forum. Bunuel  Could you walk me through how you reduced the fraction above (highlighted in blue)



Math Expert
Joined: 02 Sep 2009
Posts: 39713

Re: Ratio question [#permalink]
Show Tags
08 Mar 2014, 09:03
bparrish89 wrote: Bunuel wrote: In last examination Roger scored marks in each of 5 subjects in the following ratio 4:5:6:7:8 and got an overall score of 72%. If 50% of the maximum marks is passing and the maximum marks of each subject is the same, in how many subjects did Roger fail?A. 1 B. 2 C. 3 D. 4 E. 5 Given: A:B:C:D:E=4x:5x:6x:7x:8x, for some multiple x. Assume the maximum marks of each subject to be y, so the the maximum marks of ALL 5 subjects will be 5y. So, we have that \(4x+5x+6x+7x+8x=\frac{72}{100}*5y\) > \(30x=\frac{72*5}{100}*y\) > \(x=\frac{12}{100}*y\). \(4x=\frac{48}{100}*y\) and \(5x=\frac{60}{100}*y\), so in subject A Roger scored 48% (less than 50%) and in subject B 60% (more than 50%). Obviously in all other subjects Rogers scores will be higher than 50%.Roger failed in only one subject A. Answer: A. P.S. Please post PS questions in the PS subforum: gmatproblemsolvingps140/ and DS questions in the DS subforum: gmatdatasufficiencyds141/
No posting of PS/DS questions is allowed in the main Math forum. Bunuel  Could you walk me through how you reduced the fraction above (highlighted in blue) \(30x=\frac{72*5}{100}*y=\frac{(6*12)*5}{100}*y\) > reduce by 30=6*5: \(x=\frac{12}{100}*y\) > multiply by 4: \(4x=\frac{48}{100}*y\). Hope it's clear.
_________________
New to the Math Forum? Please read this: All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



Senior Manager
Joined: 20 Dec 2013
Posts: 267
Location: India

Re: In last examination Roger scored marks in each of 5 subjects [#permalink]
Show Tags
08 Mar 2014, 10:24
Option A. Let the marks be 4x,5x,6x,7x and 8x. Total=30x Avg.=6x Now 6x=72 X=12 On calculating Subject marks,we get 48,60,72,84 & 96. Only one subject is <50.
Posted from my mobile device



SVP
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1857
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)

Re: In last examination Roger scored marks in each of 5 subjects [#permalink]
Show Tags
09 Mar 2014, 03:26
monalimishra wrote: I did this by picking numbers. Say the max mark in each subject is 100. Then I can directly know that Roger scored 40,50,60,70,80. Since passing mark is 50% of max mark => passing mark = 50. Thus Roger failed in only 1 subject, where he scored 40.
Answer A. Though the answer A is correct, the calculations are wrong If we consider 40,50,60,70,80 as the scores, then the average comes up 60%
_________________
Kindly press "+1 Kudos" to appreciate



GMAT Club Legend
Joined: 09 Sep 2013
Posts: 15995

Re: In last examination Roger scored marks in each of 5 subjects [#permalink]
Show Tags
01 May 2015, 14:39
Hello from the GMAT Club BumpBot! Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up  doing my job. I think you may find it valuable (esp those replies with Kudos). Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Books  GMAT Club Tests  Best Prices on GMAT Courses  GMAT Mobile App  Math Resources  Verbal Resources



Intern
Joined: 16 May 2015
Posts: 15

Re: In last examination Roger scored marks in each of 5 subjects [#permalink]
Show Tags
24 May 2015, 02:10
Hi, Is my logic correct.
what i understood was 72% score implies, 72% of max that is 100% and since he got 72% in the ratios 4 5 6 7 8 therefore he got 48% of max marks in A. which is less that 50% if max marks. hence he failed in 1 subject.



GMAT Club Legend
Joined: 09 Sep 2013
Posts: 15995

Re: In last examination Roger scored marks in each of 5 subjects [#permalink]
Show Tags
19 Sep 2016, 08:19
Hello from the GMAT Club BumpBot! Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up  doing my job. I think you may find it valuable (esp those replies with Kudos). Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Books  GMAT Club Tests  Best Prices on GMAT Courses  GMAT Mobile App  Math Resources  Verbal Resources



Senior Manager
Status: DONE!
Joined: 05 Sep 2016
Posts: 409

Re: In last examination Roger scored marks in each of 5 subjects [#permalink]
Show Tags
28 Oct 2016, 10:54
[4x+5x+6x+7x+8x]/5 = 72 30x=360 x=12
4(12) = 48, which is below 50, thus we have 1 exam that he failed.




Re: In last examination Roger scored marks in each of 5 subjects
[#permalink]
28 Oct 2016, 10:54







