GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 12 Dec 2018, 10:56

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Events & Promotions

Events & Promotions in December
PrevNext
SuMoTuWeThFrSa
2526272829301
2345678
9101112131415
16171819202122
23242526272829
303112345
Open Detailed Calendar
• The winning strategy for 700+ on the GMAT

December 13, 2018

December 13, 2018

08:00 AM PST

09:00 AM PST

What people who reach the high 700's do differently? We're going to share insights, tips and strategies from data we collected on over 50,000 students who used examPAL.
• GMATbuster's Weekly GMAT Quant Quiz, Tomorrow, Saturday at 9 AM PST

December 14, 2018

December 14, 2018

09:00 AM PST

10:00 AM PST

10 Questions will be posted on the forum and we will post a reply in this Topic with a link to each question. There are prizes for the winners.

In triangle WXY, what is the length of side XY? (1) a = 45 (2) a – b

Author Message
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 51121
In triangle WXY, what is the length of side XY? (1) a = 45 (2) a – b  [#permalink]

Show Tags

18 Sep 2018, 21:13
00:00

Difficulty:

95% (hard)

Question Stats:

27% (02:03) correct 73% (01:50) wrong based on 75 sessions

HideShow timer Statistics

In triangle WXY, what is the length of side XY?

(1) a = 45
(2) a – b = 0

Attachment:

image009.gif [ 1.64 KiB | Viewed 633 times ]

_________________
e-GMAT Representative
Joined: 04 Jan 2015
Posts: 2291
Re: In triangle WXY, what is the length of side XY? (1) a = 45 (2) a – b  [#permalink]

Show Tags

19 Sep 2018, 04:28
1

Solution

To find:
• The length of side XY, in triangle WXY

Analysing Statement 1
“a = 45 degrees”

Implies,
• ∠XYW = 45 degrees
• ∠XWY = 22.5 degrees
• Thus, ∠YXW = 180 – 45 – 22.5 = 112.5 degrees

This information is not sufficient to find the length of XY

Therefore, Statement 1 is NOT sufficient to arrive at a unique answer

Analysing Statement 2
“a – b = 0”

• Implies, a = b
• Thus, XY = XZ ………. (1)
• ∠XZW = 180 - b = 180 – a
• In triangle XZW,
o $$∠ZXW + 180-a + \frac{a}{2} = 180$$
o Implies, $$∠ZXW = \frac{a}{2}$$
• Thus, XZ = ZW = 1, since ∠ZXW = ∠XWZ

Therefore, the length of XY = 1 (from (1))

Therefore, Statement 2 is sufficient to arrive at a unique answer

Hence, the correct answer is option B

_________________

Number Properties | Algebra |Quant Workshop

Success Stories
Guillermo's Success Story | Carrie's Success Story

Ace GMAT quant
Articles and Question to reach Q51 | Question of the week

Number Properties – Even Odd | LCM GCD | Statistics-1 | Statistics-2 | Remainders-1 | Remainders-2
Word Problems – Percentage 1 | Percentage 2 | Time and Work 1 | Time and Work 2 | Time, Speed and Distance 1 | Time, Speed and Distance 2
Advanced Topics- Permutation and Combination 1 | Permutation and Combination 2 | Permutation and Combination 3 | Probability
Geometry- Triangles 1 | Triangles 2 | Triangles 3 | Common Mistakes in Geometry
Algebra- Wavy line | Inequalities

Practice Questions
Number Properties 1 | Number Properties 2 | Algebra 1 | Geometry | Prime Numbers | Absolute value equations | Sets

| '4 out of Top 5' Instructors on gmatclub | 70 point improvement guarantee | www.e-gmat.com

Intern
Joined: 24 Sep 2013
Posts: 23
Location: Saudi Arabia
GPA: 3.8
WE: Project Management (Energy and Utilities)
Re: In triangle WXY, what is the length of side XY? (1) a = 45 (2) a – b  [#permalink]

Show Tags

21 Sep 2018, 09:40
EgmatQuantExpert Can you please elaborate in 2nd statement how you arrived that XZ = ZW = 1
e-GMAT Representative
Joined: 04 Jan 2015
Posts: 2291
Re: In triangle WXY, what is the length of side XY? (1) a = 45 (2) a – b  [#permalink]

Show Tags

21 Sep 2018, 09:57
vipulshahi wrote:
EgmatQuantExpert Can you please elaborate in 2nd statement how you arrived that XZ = ZW = 1

Quote:

From 2nd statement, we know a - b = 0, means a = b
As a = b, we can say in triangle XYZ, angle XYZ = angle XZY = a

Now, we can also say angle XZY + angle XZW = 180
Or, a + angle XZW = 180
Or, angle XZW = 180 - a

Considering triangle XZW,
angle XZW + angle ZXW + angle ZWX = 180
Or, (180 - a) + angle ZXW + a/2 = 180
Or, angle ZXW = a/2

As angle ZXW = angle ZWX = a/2, we can say side ZX = side ZW = 1.

Hope this helps
_________________

Number Properties | Algebra |Quant Workshop

Success Stories
Guillermo's Success Story | Carrie's Success Story

Ace GMAT quant
Articles and Question to reach Q51 | Question of the week

Number Properties – Even Odd | LCM GCD | Statistics-1 | Statistics-2 | Remainders-1 | Remainders-2
Word Problems – Percentage 1 | Percentage 2 | Time and Work 1 | Time and Work 2 | Time, Speed and Distance 1 | Time, Speed and Distance 2
Advanced Topics- Permutation and Combination 1 | Permutation and Combination 2 | Permutation and Combination 3 | Probability
Geometry- Triangles 1 | Triangles 2 | Triangles 3 | Common Mistakes in Geometry
Algebra- Wavy line | Inequalities

Practice Questions
Number Properties 1 | Number Properties 2 | Algebra 1 | Geometry | Prime Numbers | Absolute value equations | Sets

| '4 out of Top 5' Instructors on gmatclub | 70 point improvement guarantee | www.e-gmat.com

Intern
Joined: 24 Sep 2013
Posts: 23
Location: Saudi Arabia
GPA: 3.8
WE: Project Management (Energy and Utilities)
Re: In triangle WXY, what is the length of side XY? (1) a = 45 (2) a – b  [#permalink]

Show Tags

21 Sep 2018, 10:05
EgmatQuantExpert Now i got it, thank you Mam for your explanation.
Manager
Joined: 22 Jan 2014
Posts: 175
WE: Project Management (Computer Hardware)
Re: In triangle WXY, what is the length of side XY? (1) a = 45 (2) a – b  [#permalink]

Show Tags

24 Sep 2018, 02:19
Bunuel wrote:

In triangle WXY, what is the length of side XY?

(1) a = 45
(2) a – b = 0

Attachment:
image009.gif

1) a = 45*
clearly insuff.

2) a-b = 0
or a=b
in other triangle angles are a/2, 180-(a/2), and a/2
this makes common side as 1
and since a=b so XY = 1 as well
so B alone is suff.
_________________

Illegitimi non carborundum.

Re: In triangle WXY, what is the length of side XY? (1) a = 45 (2) a – b &nbs [#permalink] 24 Sep 2018, 02:19
Display posts from previous: Sort by