Percentage

Expert replies

vipinsharma: Newbie | Next Rank: 10 Posts; Posts: 9; Joined: Tue Apr 08, 2014 11:29 amFollowed by: 1 member; Thanked: 1 times

by vipinsharma » Sun Apr 27, 2014 8:07 am

A student scores 25% and failed by 30 marks while another student who scores 60% get 40 marks more than minimum required marks to pass. find the maximum marks in the exam.?

Like this post

Source: Beat The GMAT — Problem Solving | Sun Apr 27, 2014 8:07 am

GMAT/MBA Expert

Brent@GMATPrepNow: GMAT Instructor; Posts: 16207; Joined: Mon Dec 08, 2008 6:26 pmFollowed by: 1268 members; Location: Vancouver, BC; Thanked: 5254 times; GMAT Score:770

by Brent@GMATPrepNow » Sun Apr 27, 2014 9:09 am

vipinsharma wrote:A student scores 25% and failed by 30 marks while another student who scores 60% gets 40 marks more than minimum required marks to pass. find the maximum marks in the exam.?

When posting questions, please include the 5 answer choices. In many cases, the fastest approach involves using the answer choices to our advantage.
Here's one approach:
Let T = the TOTAL number of marks the test is out of (i.e., the maximum score)
Let P = the number of marks required to PASS the test

A student scores 25% and failed by 30 marks
In other words, getting 25% of the total possible marks results in a score that's 30 marks LESS THAN the number of marks required to pass.
We can write: 0.25T = P - 30
Rewrite as 0.25T + 30 = P

A student who scores 60% gets 40 marks more than minimum required marks to pass
In other words, getting 60% of the total possible marks results in a score that's 40 marks MORE THAN the number of marks required to pass.
We can write: 0.60T = P + 40
Rewrite as 0.60T - 40 = P

Since the red and blue equations are set equal to P, we can write...
0.25T + 30 = 0.60T - 40
Rearrange to get: 70 = 0.35T
Solve to get: T = 200

So, the test is out of 200 marks. So, the maximum score is 200.

ASIDE: If the answer choices had been included, it might have been faster to just start testing the answer choices.

ASIDE: If we solve for P, we see that the PASSING score for this test was 80 marks. I mention this because some students might assume that 50% was the passing score for the test.

Cheers,
Brent

Brent Hanneson - Creator of GMATPrepNow.com

Like this post

GMATGuruNY: GMAT Instructor; Posts: 15539; Joined: Tue May 25, 2010 12:04 pmFollowed by: 1906 members; Location: New York, NY; Thanked: 13060 times; GMAT Score:790

by GMATGuruNY » Sun Apr 27, 2014 1:33 pm

vipinsharma wrote:A student scores 25% and failed by 30 marks while another student who scores 60% get 40 marks more than minimum required marks to pass. find the maximum marks in the exam.?

Increasing from 25% to 60% must yield a difference of 70 marks (from 30 BELOW passing to 40 ABOVE passing).
If there are a total of 100 possible marks, the difference between 60% and 25% = 60-25 = 35.
Since the required difference of 70 marks is TWICE AS GREAT, the total number of marks must be TWICE AS GREAT as 100:
2*100 = 200.

Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3

Like this post

j_shreyans: Legendary Member; Posts: 510; Joined: Thu Aug 07, 2014 2:24 amFollowed by: 5 members; Thanked: 3 times

by j_shreyans » Sat Feb 14, 2015 11:05 am

Hi All ,

I got stuck in the last step. Please advise.

Let Minimum be M and Total be T

So 25T/100=M-30

from this we got T=(M-30)100/25 .....(|)

And 60T/100=M+40

From this we got T=(M+40)100/60 .....(||)

now we can equate these two

(M-30)100/25=(M+40)100/60

So we will get M=80

now what???

please advise.

Thanks

Shreyans

Like this post

GMAT/MBA Expert

[email protected]: Elite Legendary Member; Posts: 10392; Joined: Sun Jun 23, 2013 6:38 pmFollowed by: 511 members; Location: Palo Alto, CA; Thanked: 2867 times; GMAT Score:800

by [email protected] » Sat Feb 14, 2015 7:29 pm

Hi j_shreyans,

Now that you know that M = 80, you can plug THAT value back into either of the two original equations that you wrote and get the value of T.

Using the first equation....

T = (80-30)(100)/25

T = (50)(4)/1

T = 200

GMAT assassins aren't born, they're made,
Rich

Contact Rich at [email protected]

Like this post

Matt@VeritasPrep: GMAT Instructor; Posts: 2630; Joined: Wed Sep 12, 2012 3:32 pmFollowed by: 119 members; Location: East Bay all the way; Thanked: 625 times; GMAT Score:780

by Matt@VeritasPrep » Sun Feb 15, 2015 6:39 pm

j_shreyans wrote:Hi All ,

I got stuck in the last step. Please advise.

Let Minimum be M and Total be T

So 25T/100=M-30

So we will get M=80

now what???

You've got it all there - once you discover that M = 80, plug into the equation in green, or (1/4)T = M - 30, and you're set.

Save $100 on any VP online course!

Like this post

GMATinsight: Legendary Member; Posts: 1100; Joined: Sat May 10, 2014 11:34 pmFollowed by: 24 members; Location: New Delhi, India; Thanked: 205 times

by GMATinsight » Mon Feb 16, 2015 3:37 am

vipinsharma wrote:A student scores 25% and failed by 30 marks while another student who scores 60% get 40 marks more than minimum required marks to pass. find the maximum marks in the exam.?

Lets's say X = Total Marks

Passing Marks = 0.25 X + 30 [as per first statement of question]
Passing Marks = 0.60 X - 40 [as per first statement of question]

Both are the same therefore

0.25 X + 30 = 0.60 X - 40

i.e. 0.35 X = 30 + 40
i.e. X = 70/0.35 = 200

"GMATinsight"Bhoopendra Singh & Sushma Jha
Most Comprehensive and Affordable Video Course 2000+ CONCEPT Videos and Video Solutions
Whatsapp/Mobile: +91-9999687183 l [email protected]
Contact for One-on-One FREE ONLINE DEMO Class Call/e-mail
Most Efficient and affordable One-On-One Private tutoring fee - US$40-50 per hour

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

559 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review