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

 It is currently 16 Feb 2019, 16:31

### 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 February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar
• ### Free GMAT Algebra Webinar

February 17, 2019

February 17, 2019

07:00 AM PST

09:00 AM PST

Attend this Free Algebra Webinar and learn how to master Inequalities and Absolute Value problems on GMAT.
• ### Free GMAT Strategy Webinar

February 16, 2019

February 16, 2019

07:00 AM PST

09:00 AM PST

Aiming to score 760+? Attend this FREE session to learn how to Define your GMAT Strategy, Create your Study Plan and Master the Core Skills to excel on the GMAT.

# A shopkeeper mentally reversed the digits of a customer’s correct amou

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

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 52902
A shopkeeper mentally reversed the digits of a customer’s correct amou  [#permalink]

### Show Tags

03 Oct 2018, 23:30
00:00

Difficulty:

35% (medium)

Question Stats:

72% (01:36) correct 28% (01:27) wrong based on 46 sessions

### HideShow timer Statistics

A shopkeeper mentally reversed the digits of a customer’s correct amount of change and thus gave the customer an incorrect amount of change. If his collection showed 54 cents more than it should have, which of the following could be the correct amount of change in cents?

(A) 24
(B) 35
(C) 64
(D) 75
(E) 93

_________________
CEO
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2775
Location: India
GMAT: INSIGHT
Schools: Darden '21
WE: Education (Education)
Re: A shopkeeper mentally reversed the digits of a customer’s correct amou  [#permalink]

### Show Tags

03 Oct 2018, 23:46
1
Bunuel wrote:
A shopkeeper mentally reversed the digits of a customer’s correct amount of change and thus gave the customer an incorrect amount of change. If his collection showed 54 cents more than it should have, which of the following could be the correct amount of change in cents?

(A) 24
(B) 35
(C) 64
(D) 75
(E) 93

let, the change to be returned = ab
Chnges returned = ba

now, ab-ba = 54

i.e. (10a+b) - (10b+a) = 54

i.e. 9 (a-b) = 54

i.e. (a-b) = 6 i.e. difference of digits for correct answer should be 6 which is true for 93

_________________

Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION

Manager
Joined: 26 Apr 2011
Posts: 60
Location: India
GPA: 3.5
WE: Information Technology (Computer Software)
Re: A shopkeeper mentally reversed the digits of a customer’s correct amou  [#permalink]

### Show Tags

08 Oct 2018, 01:25
GMATinsight wrote:
Bunuel wrote:
A shopkeeper mentally reversed the digits of a customer’s correct amount of change and thus gave the customer an incorrect amount of change. If his collection showed 54 cents more than it should have, which of the following could be the correct amount of change in cents?

(A) 24
(B) 35
(C) 64
(D) 75
(E) 93

let, the change to be returned = ab
Chnges returned = ba

now, ab-ba = 54

i.e. (10a+b) - (10b+a) = 54

i.e. 9 (a-b) = 54

i.e. (a-b) = 6 i.e. difference of digits for correct answer should be 6 which is true for 93

Can you please explain a bit more? Especially the last part
_________________

Do What Your Heart Says....

Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 8880
Location: Pune, India
Re: A shopkeeper mentally reversed the digits of a customer’s correct amou  [#permalink]

### Show Tags

08 Oct 2018, 02:17
Bunuel wrote:
A shopkeeper mentally reversed the digits of a customer’s correct amount of change and thus gave the customer an incorrect amount of change. If his collection showed 54 cents more than it should have, which of the following could be the correct amount of change in cents?

(A) 24
(B) 35
(C) 64
(D) 75
(E) 93

Using Options:

If the shopkeeper had to give ab cents, he actually gave ba cents. At the end of the day, he had 54 cents extra.
It means he had a give a higher amount ab (correct amount) but gave a smaller amount ba.
So you tens digit should be greater than units digit and if you inverse the digits and subtract, you should get 54.
24, 35 - tens units less than units digit so outright rejected.
64 - 46 gives less than 20 - rejected
75 - 57 gives less than 20 - rejected
Answer 93 (93 - 39 = 54)
_________________

Karishma
Veritas Prep GMAT Instructor

Learn more about how Veritas Prep can help you achieve a great GMAT score by checking out their GMAT Prep Options >

CEO
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2775
Location: India
GMAT: INSIGHT
Schools: Darden '21
WE: Education (Education)
Re: A shopkeeper mentally reversed the digits of a customer’s correct amou  [#permalink]

### Show Tags

08 Oct 2018, 05:02
MrCleantek wrote:
GMATinsight wrote:
Bunuel wrote:
A shopkeeper mentally reversed the digits of a customer’s correct amount of change and thus gave the customer an incorrect amount of change. If his collection showed 54 cents more than it should have, which of the following could be the correct amount of change in cents?

(A) 24
(B) 35
(C) 64
(D) 75
(E) 93

let, the change to be returned = ab
Chnges returned = ba

now, ab-ba = 54

i.e. (10a+b) - (10b+a) = 54

i.e. 9 (a-b) = 54

i.e. (a-b) = 6 i.e. difference of digits for correct answer should be 6 which is true for 93

Can you please explain a bit more? Especially the last part

MrCleantek
Any Two digit number ab can be represented as 10a+b e.g. 57 = 10*5+7 and 73 = 10*7+3

Similarly, Any Three digit number abc can be represented as 100a+10b+c e.g. 257 = 100*2+10*5+7 and 473 = 100*4+10*7+3

I don't understand what problem are you facing at the end... Please highlight the part in which you need further explanation.
_________________

Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION

Manager
Joined: 26 Apr 2011
Posts: 60
Location: India
GPA: 3.5
WE: Information Technology (Computer Software)
Re: A shopkeeper mentally reversed the digits of a customer’s correct amou  [#permalink]

### Show Tags

10 Oct 2018, 22:25
Quote:
MrCleantek
Any Two digit number ab can be represented as 10a+b e.g. 57 = 10*5+7 and 73 = 10*7+3

Similarly, Any Three digit number abc can be represented as 100a+10b+c e.g. 257 = 100*2+10*5+7 and 473 = 100*4+10*7+3

I don't understand what problem are you facing at the end... Please highlight the part in which you need further explanation.

I had confusion here: i.e. (a-b) = 6 i.e. difference of digits for correct answer should be 6 which is true for 93
But now I got it. I was using 54 and trying to come up with 93. I dont know what was I doing. Now I got it. 93 and 39 lead to 54 as diff. Diff between digits is also 6. So that is the answer
_________________

Do What Your Heart Says....

Re: A shopkeeper mentally reversed the digits of a customer’s correct amou   [#permalink] 10 Oct 2018, 22:25
Display posts from previous: Sort by

# A shopkeeper mentally reversed the digits of a customer’s correct amou

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

 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®.