• Economist Test Prep
    Free Trial & Practice Exam
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

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

    Available with Beat the GMAT members only code

    MORE DETAILS
    EMPOWERgmat Slider
  • 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
  • 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
  • Veritas Prep
    Free Veritas GMAT Class
    Experience Lesson 1 Live Free

    Available with Beat the GMAT members only code

    MORE DETAILS
    Veritas Prep
  • 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
  • Magoosh
    Magoosh
    Study with Magoosh GMAT prep

    Available with Beat the GMAT members only code

    MORE DETAILS
    Magoosh
  • PrepScholar GMAT
    5 Day FREE Trial
    Study Smarter, Not Harder

    Available with Beat the GMAT members only code

    MORE DETAILS
    PrepScholar GMAT
  • 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

Is x+y equal to 3.6 ? I need help here

This topic has 1 expert reply and 0 member replies

Is x+y equal to 3.6 ? I need help here

Post Mon Sep 25, 2017 6:22 pm
Is x+y equal to 3.6 ?

(1) x > 1.7 or x = 1.7
(2) y > 1.9

The OA is C.

I know each statement alone is not sufficient, but why together they are sufficient? If y=2 and x=1.7 then x+y=3.7. What is wrong with my calculus?

  • +1 Upvote Post
  • Quote
  • Flag

GMAT/MBA Expert

ErikaPrepScholar Master | Next Rank: 500 Posts
Joined
20 Jul 2017
Posted:
322 messages
Followed by:
4 members
Upvotes:
86
GMAT Score:
770
Most Active Expert Most Responsive Expert
Post Tue Sep 26, 2017 6:31 am
The key here is to recognize that this is a "yes"/"no" Data Sufficiency question. This means that the statement is sufficient if we can prove EITHER 1) that, yes, x + y will always equal 3.6 OR 2) that, no, x + y will never equal 3.6.

When we combine the statements, we know that x is, at its smallest, 1.7.
If x = 1.7 and x+y=3.6:

1.7 + y = 3.6
y = 1.9

However, we know that y must be greater than 1.9. So we know for a fact that x + y will never equal 3.6: x + y will always be greater than 3.6. This is sufficient to answer "no", so the statements are sufficient together.

_________________


Erika John - Content Manager/Lead Instructor
http://gmat.prepscholar.com/gmat/s/

Learn about our exclusive savings for BTG members (up to 25% off) and our 5 day free trial

Check out our new PrepScholar GMAT YouTube channel, and read our expert guides on the PrepScholar GMAT blog

  • +1 Upvote Post
  • Quote
  • Flag

Best Conversation Starters

1 Roland2rule 181 topics
2 lheiannie07 110 topics
3 ardz24 60 topics
4 LUANDATO 55 topics
5 swerve 52 topics
See More Top Beat The GMAT Members...

Most Active Experts

1 image description Brent@GMATPrepNow

GMAT Prep Now Teacher

153 posts
2 image description GMATGuruNY

The Princeton Review Teacher

125 posts
3 image description Scott@TargetTestPrep

Target Test Prep

123 posts
4 image description Rich.C@EMPOWERgma...

EMPOWERgmat

111 posts
5 image description EconomistGMATTutor

The Economist GMAT Tutor

83 posts
See More Top Beat The GMAT Experts