• e-gmat Exclusive Offer
    Get 300+ Practice Questions
    25 Video lessons and 6 Webinars for FREE

    Available with Beat the GMAT members only code

    MORE DETAILS
    e-gmat Exclusive Offer
  • Economist Test Prep
    Free Trial & Practice Exam
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    Economist Test Prep
  • Veritas Prep
    Free Veritas GMAT Class
    Experience Lesson 1 Live Free

    Available with Beat the GMAT members only code

    MORE DETAILS
    Veritas Prep
  • Target Test Prep
    5-Day Free Trial
    5-day free, full-access trial TTP Quant

    Available with Beat the GMAT members only code

    MORE DETAILS
    Target Test Prep
  • EMPOWERgmat Slider
    1 Hour Free
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    EMPOWERgmat Slider
  • Kaplan Test Prep
    Free Practice Test & Review
    How would you score if you took the GMAT

    Available with Beat the GMAT members only code

    MORE DETAILS
    Kaplan Test Prep
  • PrepScholar GMAT
    5 Day FREE Trial
    Study Smarter, Not Harder

    Available with Beat the GMAT members only code

    MORE DETAILS
    PrepScholar GMAT
  • Varsity Tutors
    Award-winning private GMAT tutoring
    Register now and save up to $200

    Available with Beat the GMAT members only code

    MORE DETAILS
    Varsity Tutors
  • examPAL
    Most awarded test prep in the world
    Now free for 30 days

    Available with Beat the GMAT members only code

    MORE DETAILS
    examPAL
  • Magoosh
    Magoosh
    Study with Magoosh GMAT prep

    Available with Beat the GMAT members only code

    MORE DETAILS
    Magoosh

weight problem

This topic has 7 expert replies and 4 member replies
sportypk Junior | Next Rank: 30 Posts Default Avatar
Joined
31 Mar 2008
Posted:
15 messages

weight problem

Post Fri May 30, 2008 8:57 am
If Jake loses 8 pounds, he will weigh twice as much as his
sister. Together they now weigh 278 pounds. What is Jake's
present weight, in pounds?
(A) 131
(B) 135
(C) 139
(D) 147
(E) 188

the OA is 188. how?

  • +1 Upvote Post
  • Quote
  • Flag

GMAT/MBA Expert

Post Wed Jun 24, 2015 7:17 am
GMATGuruNY wrote:
sportypk wrote:
If Jake loses 8 pounds, he will weigh twice as much as his
sister. Together they now weigh 278 pounds. What is Jake�s
present weight, in pounds?
(A) 131
(B) 135
(C) 139
(D) 147
(E) 188
ALWAYS KEEP YOUR EYE ON THE ANSWER CHOICES.

If Jake loses 8 pounds, he will weigh twice as much as his sister.
j-8 = 2s
j = 2s + 8 = even + even = even.

Since Jake's weight must be an EVEN VALUE, the correct answer is E.
Sweeeeeeeeeet! Smile

Cheers,
Brent

_________________
Brent Hanneson – Founder of GMATPrepNow.com
Use our video course along with Beat The GMAT's free 60-Day Study Guide

Check out the online reviews of our course
Come see all of our free resources

  • +1 Upvote Post
  • Quote
  • Flag
GMAT Prep Now's comprehensive video course can be used in conjunction with Beat The GMAT’s FREE 60-Day Study Guide and reach your target score in 2 months!

GMAT/MBA Expert

Post Wed Jun 24, 2015 9:37 am
Hi All,

The answer choices in this question are 'spread out' in such a way that we can get to the correct answer with just a bit of logical thinking.

We're told that the total weight of Jake and his sister = 278 pounds. We're also told that if Jake LOST 8 pounds, he would TWICE as much as his sister....

This means that Jake weighs MORE than twice his sister RIGHT NOW. Since the total is 278 pounds, Jake's weight MUST make up MOST of that total weight (a lot more than half). There's only one answer that fits....

Final Answer: E

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

_________________
Contact Rich at Rich.C@empowergmat.com

  • +1 Upvote Post
  • Quote
  • Flag
DavidP Site Admin
Joined
17 Feb 2008
Posted:
387 messages
Followed by:
28 members
Upvotes:
17
Post Fri May 30, 2008 9:00 am
x = weight of Jake's sister

2x + 8 = Jake's weight

278 = Jake's sister's weight + Jake's weight

278 = x + (2x + 8)

278 = 3x + 8

270 = 3x

x = 90

Thus, Jake's weight = 2x + 8 = 2*90 + 8 = 188

  • +1 Upvote Post
  • Quote
  • Flag
egybs Master | Next Rank: 500 Posts Default Avatar
Joined
14 May 2008
Posted:
178 messages
Upvotes:
16
Test Date:
08/2008
GMAT Score:
99%+
Post Fri May 30, 2008 9:08 am
Even easier -

we know that

J-8 = 2S
Therefore S = (J-8 )/2

So J + .5J -4 = 278

(3/2)J = 282
J = 188

  • +1 Upvote Post
  • Quote
  • Flag
sportypk Junior | Next Rank: 30 Posts Default Avatar
Joined
31 Mar 2008
Posted:
15 messages
Post Fri May 30, 2008 9:19 am
wow i feel like the queen of silly mistakes...thanks guys...

  • +1 Upvote Post
  • Quote
  • Flag
Post Wed Jun 24, 2015 3:21 am
sportypk wrote:
If Jake loses 8 pounds, he will weigh twice as much as his
sister. Together they now weigh 278 pounds. What is Jake�s
present weight, in pounds?
(A) 131
(B) 135
(C) 139
(D) 147
(E) 188

the OA is 188. how?
Solution:

This problem can be solved as a simple word problem in which we must convert words to math. Before we create our equations, we want to define some variables.

J = Jake’s current weight, in pounds

S = Sister’s current weight, in pounds

We are told that “If Jake loses 8 pounds, he will weigh twice as much as his sister." We put this into an equation:

J - 8 = 2S

We can isolate J by adding 8 to 2S:

J = 2S + 8 (Equation 1)

Next, we are told that “Together they now weigh 278 pounds.” We can also put this into an equation.

J + S = 278 (Equation 2)

To solve this equation, we can substitute 2S + 8 from Equation 1 for the variable J in Equation 2:

2S + 8 + S = 278

3S = 270

S = 90

We now know that the sister weighs S = 90 pounds, and we can plug that value into either equation to determine J. Let’s plug 90 for S into equation 2:

J + 90 = 278

J = 188

Answer: E

_________________
Scott Woodbury-Stewart Founder and CEO

  • +1 Upvote Post
  • Quote
  • Flag

GMAT/MBA Expert

Post Wed Jun 24, 2015 6:15 am
sportypk wrote:
If Jake loses 8 pounds, he will weigh twice as much as his
sister. Together they now weigh 278 pounds. What is Jake�s
present weight, in pounds?
(A) 131
(B) 135
(C) 139
(D) 147
(E) 188
Here's a solution that uses one variable.

Let x = Jake's present weight in pounds
So, x - 8 = Jake's hypothetical weight IF he were to lose 8 pounds

If Jake loses 8 pounds, he will weigh twice as much as his sister.
In other words, the sister weighs HALF as much as Jake's hypothetical weight of x - 8 pounds
So, (x - 8)/2 = sister's present weight

Together they NOW weigh 278 pounds.
So, Jake's present weight + sister's present weight = 278
So, x + (x - 8)/2 = 278
Eliminate fractions by multiplying both sides by 2 to get: 2x + (x - 8) = 556
Simplify: 3x - 8 = 556
Add 8 to both sides: 3x = 564
Solve: x = 188 = E

Cheers,
Brent

_________________
Brent Hanneson – Founder of GMATPrepNow.com
Use our video course along with Beat The GMAT's free 60-Day Study Guide

Check out the online reviews of our course
Come see all of our free resources

  • +1 Upvote Post
  • Quote
  • Flag
GMAT Prep Now's comprehensive video course can be used in conjunction with Beat The GMAT’s FREE 60-Day Study Guide and reach your target score in 2 months!

GMAT/MBA Expert

Post Wed Jun 24, 2015 6:40 am
sportypk wrote:
If Jake loses 8 pounds, he will weigh twice as much as his
sister. Together they now weigh 278 pounds. What is Jake�s
present weight, in pounds?
(A) 131
(B) 135
(C) 139
(D) 147
(E) 188
ALWAYS KEEP YOUR EYE ON THE ANSWER CHOICES.

If Jake loses 8 pounds, he will weigh twice as much as his sister.
j-8 = 2s
j = 2s + 8 = even + even = even.

Since Jake's weight must be an EVEN VALUE, the correct answer is E.

_________________
Mitch Hunt
GMAT Private Tutor
GMATGuruNY@gmail.com
If you find one of my posts helpful, please take a moment to click on the "UPVOTE" icon.
Available for tutoring in NYC and long-distance.
For more information, please email me at GMATGuruNY@gmail.com.

  • +1 Upvote Post
  • Quote
  • Flag
Free GMAT Practice Test How can you improve your test score if you don't know your baseline score? Take a free online practice exam. Get started on achieving your dream score today! Sign up now.
egybs Master | Next Rank: 500 Posts Default Avatar
Joined
14 May 2008
Posted:
178 messages
Upvotes:
16
Test Date:
08/2008
GMAT Score:
99%+
Post Wed Jun 24, 2015 7:10 am
GMAT 'experts', I still like my solution from 7 years ago better.

  • +1 Upvote Post
  • Quote
  • Flag

GMAT/MBA Expert

Post Wed Jun 24, 2015 1:28 pm
Rich.C@EMPOWERgmat.com wrote:
Hi All,

The answer choices in this question are 'spread out' in such a way that we can get to the correct answer with just a bit of logical thinking.

We're told that the total weight of Jake and his sister = 278 pounds. We're also told that if Jake LOST 8 pounds, he would TWICE as much as his sister....

This means that Jake weighs MORE than twice his sister RIGHT NOW. Since the total is 278 pounds, Jake's weight MUST make up MOST of that total weight (a lot more than half). There's only one answer that fits....

Final Answer: E

GMAT assassins aren't born, they're made,
Rich
Another sweeeeet answer!
And here I'm using algebra like some sucker!! Smile

I love seeing how many approaches one can take with a GMAT math question!!!

I've already reached my exclamation mark quota for the day, so I hope no one else presents more awesome approaches.

Cheers,
Brent

_________________
Brent Hanneson – Founder of GMATPrepNow.com
Use our video course along with Beat The GMAT's free 60-Day Study Guide

Check out the online reviews of our course
Come see all of our free resources

  • +1 Upvote Post
  • Quote
  • Flag
GMAT Prep Now's comprehensive video course can be used in conjunction with Beat The GMAT’s FREE 60-Day Study Guide and reach your target score in 2 months!

GMAT/MBA Expert

Ian Stewart GMAT Instructor
Joined
02 Jun 2008
Posted:
2285 messages
Followed by:
346 members
Upvotes:
1090
GMAT Score:
780
Post Wed Jun 24, 2015 3:15 pm
Mitch's solution is obviously fastest, but there is a no-variable solution we can use if the answer choices don't allow for any trick: if Jake loses 8 pounds, then together they'll weigh 270 pounds, and if Jake would then weigh twice as much as his sister, the ratio of their weights is 2 to 1, so Jake would weigh 2/3 of 270, or 180 pounds. Add back the 8, and 188 is the answer.

_________________
If you are looking for online GMAT math tutoring, or if you are interested in buying my advanced Quant books and problem sets, please contact me at ianstewartgmat at gmail.com

  • +1 Upvote Post
  • Quote
  • Flag

Best Conversation Starters

1 lheiannie07 108 topics
2 ardz24 67 topics
3 Roland2rule 63 topics
4 LUANDATO 50 topics
5 swerve 43 topics
See More Top Beat The GMAT Members...

Most Active Experts

1 image description GMATGuruNY

The Princeton Review Teacher

152 posts
2 image description Jeff@TargetTestPrep

Target Test Prep

106 posts
3 image description Rich.C@EMPOWERgma...

EMPOWERgmat

103 posts
4 image description Scott@TargetTestPrep

Target Test Prep

96 posts
5 image description Max@Math Revolution

Math Revolution

86 posts
See More Top Beat The GMAT Experts