• Magoosh
    Magoosh
    Study with Magoosh GMAT prep

    Available with Beat the GMAT members only code

    MORE DETAILS
    Magoosh
  • EMPOWERgmat Slider
    1 Hour Free
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

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

    Available with Beat the GMAT members only code

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

    Available with Beat the GMAT members only code

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

    Available with Beat the GMAT members only code

    MORE DETAILS
    PrepScholar GMAT
  • 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

In the xy coordinate plane, . . .

This topic has 1 expert reply and 0 member replies

In the xy coordinate plane, . . .

Post Thu Sep 14, 2017 2:22 pm
In the xy coordinate plane, does the point (3,4) lie on line t?

(1) The line 5y-45=-x is perpendicular to the line t.

(2) The line with the equation y=(3/4)x-11 intersects the line t when y=-11.

The OA is C.

Please show a step by step approach here and explain why it is not sufficient each statement alone. Thanks.

  • +1 Upvote Post
  • Quote
  • Flag
Post Thu Sep 14, 2017 11:03 pm
Vincen wrote:
In the xy coordinate plane, does the point (3,4) lie on line t?

(1) The line 5y-45=-x is perpendicular to the line t.

(2) The line with the equation y=(3/4)x-11 intersects the line t when y=-11.

The OA is C.

Please show a step by step approach here and explain why it is not sufficient each statement alone. Thanks.
Say the equation of line t is given by y = mx + c; where m = magnitude of slopes of the line and c = y-intercept

Statement 1: The line 5y-45=-x is perpendicular to the line t.

If a line is perpendicular to each other, the product of their magnitude of slopes is equal to - 1.

Let's find out the magnitude of the line 5y - 45 = -x

We can write 5y - 45 = -x as y = (-1/5)x + 45/5 => magnitude = -1/5

=> m.(-1/5) = - 1

m = 5. Thus, the magnitude of the line t is 5, however, we do not have any idea about c. We cannot determine whether the point (3,4) lies on line t. Insufficient.

Statement 2: The line with the equation y=(3/4)x - 11 intersects the line t when y = -11.

By plugging-in y = -11 in the equation y = (3/4)x - 11, we get -11 = 3x/4 - 11 => x = 0.

Thus, the equation of line t is y = c. however, we do not have any idea about c. We cannot determine whether the point (3,4) lies on line t. Insufficient.

Statement 1 & 2:

Even after combining the two statements, we cannot get the value of c. Insufficient.

The correct answer: C

Hope this helps!

Download free ebook: Manhattan Review GMAT Quantitative Question Bank Guide

-Jay
_________________
Manhattan Review GMAT Prep

Locations: New York | Jakarta | Nanjing | Berlin | and many more...

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

  • +1 Upvote Post
  • Quote
  • Flag

Best Conversation Starters

1 lheiannie07 112 topics
2 Roland2rule 74 topics
3 ardz24 67 topics
4 LUANDATO 53 topics
5 swerve 47 topics
See More Top Beat The GMAT Members...

Most Active Experts

1 image description GMATGuruNY

The Princeton Review Teacher

155 posts
2 image description Jeff@TargetTestPrep

Target Test Prep

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

EMPOWERgmat

100 posts
4 image description Scott@TargetTestPrep

Target Test Prep

98 posts
5 image description EconomistGMATTutor

The Economist GMAT Tutor

89 posts
See More Top Beat The GMAT Experts