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

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

Does x + y = 5?

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Legendary Member
Posts: 1622
Joined: Thu Mar 01, 2018 7:22 amFollowed by: 2 members
by Gmat_mission » Sun May 13, 2018 10:27 am

Timer

00:00

Answers

A

B

C

D

E

Stats

Difficulty—

Does x + y = 5?

(1) 4x + y = 17
(2) x + 4y = 8

[spoiler]OA=C[/spoiler].

How can I show that the correct answer is the option C? Could someone give me a good explanation? Please. Thanks.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Data Sufficiency |
Legendary Member
Posts: 2898
Joined: Thu Sep 07, 2017 2:49 pmFollowed by: 5 members
Thanked: 6 times

by Vincen » Sun May 13, 2018 11:11 am
Gmat_mission wrote:Does x + y = 5?

(1) 4x + y = 17
(2) x + 4y = 8

[spoiler]OA=C[/spoiler].

How can I show that the correct answer is the option C? Could someone give me a good explanation? Please. Thanks.
Hello Gmat_mission.

Let's take a look at your question.

x + y = 5?

(1) 4x + y = 17

Since we have two variables and one equation, we can not conclude anything here. Hence, this statement IS NOT SUFFICIENT.

(2) x + 4y = 8

Again, we have two variables and one equation, we can not conclude anything. Hence, this statement IS NOT SUFFICIENT.

(1) 4x + y = 17 and (2) x + 4y = 8

Now, if we add both equations we will get: $$5x+5y=25$$ $$\Rightarrow\ \ \ x+y=5.\ $$ Since we could give an answer to the original question, then we conclude that both statements together are SUFFICIENT.

Therefore, the correct answer is the option C.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1