text: GMAT Question of the Day - Daily to your Mailbox; hard ones only
  
   It is currently 23 May 2019, 11:59
  
  ### 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
  
  # If a and b are two-digit numbers that share the same digits,
  
  Author Message
  TAGS:
  
  ### Hide Tags
  
  Intern
  Joined: 12 May 2005
  Posts: 29
  If a and b are two-digit numbers that share the same digits,  [#permalink]
  
  ### Show Tags
  
  25 May 2010, 06:47
  1
  9
  00:00
  
  Difficulty:
  
  55% (hard)
  
  Question Stats:
  
  64% (02:05) correct 36% (02:02) wrong based on 276 sessions
  
  ### HideShow timer Statistics
  
  If a and b are two-digit numbers that share the same digits, except in reverse order, then what is the sum of a and b?
  
  (1) a-b=45
  (2) The difference between the two digits in each number is 5.
  Math Expert
  Joined: 02 Sep 2009
  Posts: 55266
  Re: Number Properties - DS  [#permalink]
  
  ### Show Tags
  
  25 May 2010, 07:04
  3
  1
  srichaks wrote:
  Q:If a and b are two-digit numbers that share the same digits, except in reverse order, then what is the sum of a and b?
  (1) a-b=45
  (2) The difference between the two digits in each number is 5.
  
  OA:E
  
  Any two digit integer $$n$$ can be expressed as $$n=10x+y$$, where $$x$$ and $$y$$ are digits, $$x>0$$.
  
  Given: $$a=10x+y$$ and $$b=10y+x$$. Q: $$a+b=11(x+y)=?$$
  
  (1) $$a-b=10x+y-10y-x=45$$ --> $$x-y=5$$. Multiple choices for x and y: (9,4), (8, 3), (7, 2), (6, 1). Not sufficient.
  
  (2) $$x-y=5$$. Same info as above. Not sufficient.
  
  (1)+(2) No new info. Not sufficient.
  
  _________________
  Intern
  Joined: 12 May 2005
  Posts: 29
  Re: Number Properties - DS  [#permalink]
  
  ### Show Tags
  
  25 May 2010, 18:42
  Thanks Bunuel!. Great explanation.
  Manager
  Joined: 05 Mar 2010
  Posts: 165
  Re: Number Properties - DS  [#permalink]
  
  ### Show Tags
  
  29 May 2010, 07:09
  I dont understand the "except in reverse order" part???????
  _________________
  Success is my Destiny
  Math Expert
  Joined: 02 Sep 2009
  Posts: 55266
  Re: Number Properties - DS  [#permalink]
  
  ### Show Tags
  
  29 May 2010, 07:20
  hardnstrong wrote:
  I dont understand the "except in reverse order" part???????
  
  It means that if digits in $$a$$ are $$xy$$, then in $$b$$ the digits are $$yx$$ (in reverse order).
  
  According to the solution above there are 5 pairs of $$a$$ and $$b$$ possible satisfying both statements (94 and 49, 83 and 38, 72 and 27, 61 and 16). So multiple answer to $$a+b$$. Not sufficient.
  
  Hope it's clear.
  _________________
  Manager
  Joined: 05 Mar 2010
  Posts: 165
  Re: Number Properties - DS  [#permalink]
  
  ### Show Tags
  
  30 May 2010, 06:27
  Bunuel wrote:
  hardnstrong wrote:
  I dont understand the "except in reverse order" part???????
  
  It means that if digits in $$a$$ are $$xy$$, then in $$b$$ the digits are $$yx$$ (in reverse order).
  
  According to the solution above there are 5 pairs of $$a$$ and $$b$$ possible satisfying both statements (94 and 49, 83 and 38, 72 and 27, 61 and 16). So multiple answer to $$a+b$$. Not sufficient.
  
  Hope it's clear.
  
  This is the confusing part in this question............ except in reverse order means they cannot be in reverse order (so if a = xy then b cannot be yx)
  
  Dont you think "except in reverse order" takes question is completely different direction, or should it be "in reverse order"
  _________________
  Success is my Destiny
  Math Expert
  Joined: 02 Sep 2009
  Posts: 55266
  Re: Number Properties - DS  [#permalink]
  
  ### Show Tags
  
  30 May 2010, 06:40
  hardnstrong wrote:
  Bunuel wrote:
  hardnstrong wrote:
  I dont understand the "except in reverse order" part???????
  
  It means that if digits in $$a$$ are $$xy$$, then in $$b$$ the digits are $$yx$$ (in reverse order).
  
  According to the solution above there are 5 pairs of $$a$$ and $$b$$ possible satisfying both statements (94 and 49, 83 and 38, 72 and 27, 61 and 16). So multiple answer to $$a+b$$. Not sufficient.
  
  Hope it's clear.
  
  This is the confusing part in this question............ except in reverse order means they cannot be in reverse order (so if a = xy then b cannot be yx)
  
  Dont you think "except in reverse order" takes question is completely different direction, or should it be "in reverse order"
  
  Not a perfect wording - agree. "except in reverse order" here means "but in reverse order".
  _________________
  Non-Human User
  Joined: 09 Sep 2013
  Posts: 11005
  Re: If a and b are two-digit numbers that share the same digits,  [#permalink]
  
  ### Show Tags
  
  15 Sep 2018, 10:32
  Hello from the GMAT Club BumpBot!
  
  Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).
  
  Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
  _________________
  Re: If a and b are two-digit numbers that share the same digits,   [#permalink] 15 Sep 2018, 10:32
  Display posts from previous: Sort by
metadata: {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0}