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

It is currently 21 Nov 2018, 04:08

Close

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
Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel
Events & Promotions in November
PrevNext
SuMoTuWeThFrSa
28293031123
45678910
11121314151617
18192021222324
2526272829301
Open Detailed Calendar
  • All GMAT Club Tests are Free and open on November 22nd in celebration of Thanksgiving Day!

     November 22, 2018

     November 22, 2018

     10:00 PM PST

     11:00 PM PST

    Mark your calendars - All GMAT Club Tests are free and open November 22nd to celebrate Thanksgiving Day! Access will be available from 0:01 AM to 11:59 PM, Pacific Time (USA)
  • Free lesson on number properties

     November 23, 2018

     November 23, 2018

     10:00 PM PST

     11:00 PM PST

    Practice the one most important Quant section - Integer properties, and rapidly improve your skills.

10^x + 10^y + 10^z = n, where x, y, and z are positive integers. Which

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 50729
10^x + 10^y + 10^z = n, where x, y, and z are positive integers. Which  [#permalink]

Show Tags

New post 28 Oct 2018, 22:56
00:00
A
B
C
D
E

Difficulty:

  95% (hard)

Question Stats:

30% (01:33) correct 70% (01:40) wrong based on 64 sessions

HideShow timer Statistics

\(10^x + 10^y + 10^z = n\), where x, y, and z are positive integers. Which of the following could be the total number of zeroes, to the left of the decimal point, contained in n?

I. x + y
II. y – z
III. z

A. III only
B. I and II only
C. I and III only
D. II and III only
E. I, II, and III

_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Senior Manager
Senior Manager
User avatar
P
Joined: 18 Jul 2018
Posts: 379
Location: India
Concentration: Finance, Marketing
WE: Engineering (Energy and Utilities)
Premium Member CAT Tests
Re: 10^x + 10^y + 10^z = n, where x, y, and z are positive integers. Which  [#permalink]

Show Tags

New post 29 Oct 2018, 00:02
Consider x as 1, y as 3, z as 2. Then n = 1110. the total number of zeros to the left of the decimal point is 1.

Statement 2 is possible as y-z = 3-2 = 1.

Since x,y and z are positive integers. min value of x+y is 2. But if x is 1 and y is 1 and z is 2. then n = 120. only 1 zero. cannot be possible.
Statement 1 is not possible.

If x is 3, y is 2 and z is 1. then n will contain 1 zero. Hence statement 3 is possible.

Only 2 and 3 are possible.

D is the answer.
_________________

When you want something, the whole universe conspires in helping you achieve it.

Manager
Manager
User avatar
S
Joined: 09 Jun 2018
Posts: 152
Location: United States
GPA: 3.95
WE: Manufacturing and Production (Energy and Utilities)
GMAT ToolKit User Premium Member CAT Tests
10^x + 10^y + 10^z = n, where x, y, and z are positive integers. Which  [#permalink]

Show Tags

New post 30 Oct 2018, 12:14
Afc0892 wrote:
Since x,y and z are positive integers. min value of x+y is 2. But if x is 1 and y is 1 and z is 2. then n = 120. only 1 zero. cannot be possible.
Statement 1 is not possible.



Statement 1 is also possible. Consider x = 1, y = 1, z = 3.

Then you have 10 + 10 + 1000 = 1020
1020 has 2 zeros to the left of the decimal point, i.e. in the units place and the hundred's place and hence Statement 1 is also possible.

I think the catch is "total" number of zeros. The question does not ask number of zeros until you reach a non-zero number starting from the units digit and going left.

Statement 2 is possible. Consider, x = 1, y = 3, z = 2, hence n = 1110, y-z = 1 is satisfied.

Statement 3 is possible. Consider, x = 3, y = 2, z = 1, hence n = 1110, z = 1 is satisfied.

Hence all three statements are possible.

Option E
_________________

If you found this relevant and useful, please Smash that Kudos button!

GMAT Club Bot
10^x + 10^y + 10^z = n, where x, y, and z are positive integers. Which &nbs [#permalink] 30 Oct 2018, 12:14
Display posts from previous: Sort by

10^x + 10^y + 10^z = n, where x, y, and z are positive integers. Which

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.