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.

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Re: Number Properties - DS [#permalink]
25 May 2010, 06:04

Expert's post

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.

Please explain your answer in detail including why each choice is right or wrong?

Re: Number Properties - DS [#permalink]
25 May 2010, 21:55

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.

Please explain your answer in detail including why each choice is right or wrong?

Re: Number Properties - DS [#permalink]
29 May 2010, 06:20

Expert's post

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.

Re: Number Properties - DS [#permalink]
30 May 2010, 05:27

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" _________________

Re: Number Properties - DS [#permalink]
30 May 2010, 05:40

Expert's post

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". _________________

Re: If a and b are two-digit numbers that share the same digits, [#permalink]
29 Jan 2014, 12:19

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. _________________

I couldn’t help myself but stay impressed. young leader who can now basically speak Chinese and handle things alone (I’m Korean Canadian by the way, so...