BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

R = ?

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 394
Joined: Sun Jul 02, 2017 10:59 am
Thanked: 1 times
Followed by:5 members

R = ?

by AbeNeedsAnswers » Mon Jul 03, 2017 8:39 pm

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

If p ≠ 0 and p - (1-p^2)/p = r/p, then r =

A) p + 1

B) 2p - 1

C) p^2+ 1

D) 2p^2 - 1

E) p^2 + p - 1

D
Top
Source: — Problem Solving |
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Mon Jul 03, 2017 9:18 pm
AbeNeedsAnswers wrote:If p ≠ 0 and p - (1-p^2)/p = r/p, then r =

A) p + 1

B) 2p - 1

C) p^2+ 1

D) 2p^2 - 1

E) p^2 + p - 1
Let p=-1.

Substituting p=-1 into p - (1-p²)/p = r/p, we get:
-1 - [1 - (-1)²]/-1 = r/(-1)
-1 - 0 = -r
-1 = -r
r = 1.

Since the question stem asks for the value of r, our target value is r=1.
Now plug p=-1 into the answers to see which yields our target value of 1.
Only D works:
2p² - 1 = 2(-1)² - 1 = 1.

The correct answer is D.
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
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3008
Joined: Mon Aug 22, 2016 6:19 am
Location: Grand Central / New York
Thanked: 470 times
Followed by:34 members

by Jay@ManhattanReview » Mon Jul 03, 2017 9:26 pm
AbeNeedsAnswers wrote:If p ≠ 0 and p - (1-p^2)/p = r/p, then r =

A) p + 1

B) 2p - 1

C) p^2+ 1

D) 2p^2 - 1

E) p^2 + p - 1

D
We have p - (1-p^2)/p = r/p

=> [p^2 -(1-p^2)]/p = r/p; taking LCM of LHS

Since p ≠ 0, we can cancel p from both the sides.

=> p^2 -(1-p^2) = r

=> r = p^2 -1 + p^2

[spoiler]r = 2p^2 -1[/spoiler]

The correct answer: D

Hope this helps!

Download free ebook: Manhattan Review GMAT Quantitative Question Bank Guide

-Jay
_________________
Manhattan Review GMAT Prep

Locations: New York | Barcelona | Manila | Melbourne | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 2095
Joined: Tue Dec 04, 2012 3:22 pm
Thanked: 1443 times
Followed by:247 members

by ceilidh.erickson » Tue Jul 04, 2017 8:12 am
p - (1 - p²)/p = r/p

Start by multiplying both sides by p:
p[p - (1 - p²)/p = r/p]
p² - (1 - p²) = r
p² - 1 + p² = r
2p² - 1 = r

The answer is D.
Ceilidh Erickson
EdM in Mind, Brain, and Education
Harvard Graduate School of Education
Top
GMAT Instructor
Posts: 2630
Joined: Wed Sep 12, 2012 3:32 pm
Location: East Bay all the way
Thanked: 625 times
Followed by:119 members
GMAT Score:780

by Matt@VeritasPrep » Wed Jul 05, 2017 1:01 am
p - (1 - p²)/p = r/p

multiply both sides by p:

p² - (1 - p²) = r

do the subtraction on the left side:

2p² - 1 = r
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 8083
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members

by Scott@TargetTestPrep » Wed Jul 12, 2017 4:27 pm
AbeNeedsAnswers wrote:If p ≠ 0 and p - (1-p^2)/p = r/p, then r =

A) p + 1

B) 2p - 1

C) p^2+ 1

D) 2p^2 - 1

E) p^2 + p - 1
Let's simplify the given equation p - (1-p^2)/p = r/p by multiplying both sides by p:

p^2 - (1-p^2) = r

p^2 - 1 + p^2 = r

2p^2 - 1 = r

Answer: D

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage
Top

GMAT/MBA Expert

User avatar
Elite Legendary Member
Posts: 10392
Joined: Sun Jun 23, 2013 6:38 pm
Location: Palo Alto, CA
Thanked: 2867 times
Followed by:511 members
GMAT Score:800

by [email protected] » Sat Jun 09, 2018 5:57 pm
Hi All,

We're told that P ≠ 0 and P - (1 - P^2)/P = R/P. We're asked for the value of R. This question can be solved in a couple of different ways, including by TESTing VALUES.

IF....P=2, then we have....

2 - [(1 - 4)/2] = R/2
2 - ( -3/2) = R/2
4/2 - (-3/2) = R/2
7/2 = R/2
7 = R

So we're looking for an answer that equals 7 when P=2. There's only one answer that matches...

Final Answer: D

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image
Top
Post new topic Post Reply
• Page 1 of 1