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

 It is currently 22 Aug 2019, 04:36 ### 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. ### Request Expert Reply # Each digit in the two-digit number G is halved to form a new

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

### Hide Tags

VP  Joined: 14 May 2006
Posts: 1150
Each digit in the two-digit number G is halved to form a new  [#permalink]

### Show Tags

5
35 00:00

Difficulty:   55% (hard)

Question Stats: 63% (02:17) correct 37% (01:49) wrong based on 734 sessions

### HideShow timer Statistics

Each digit in the two-digit number G is halved to form a new two-digit number H. Which of the following could be the sum of G and H?

A. 153
B. 150
C. 137
D. 129
E. 89

Originally posted by u2lover on 08 Aug 2006, 13:49.
Last edited by Bunuel on 14 Aug 2013, 00:40, edited 1 time in total.
Edited the question and added the OA.
##### Most Helpful Expert Reply
Math Expert V
Joined: 02 Sep 2009
Posts: 57237
Re: Each digit in the two-digit number G is halved to form a new  [#permalink]

### Show Tags

15
1
18
u2lover wrote:
Each digit in the two-digit number G is halved to form a new two-digit number H. Which of the following could be the sum of G and H?

A. 153
B. 150
C. 137
D. 129
E. 89

Two-step solution:

G + G/2 = 3G/2 --> the sum is a multiple of 3.

G is a two-digit number --> G < 100 --> 3G/2 < 150.

Among the answer choices the only multiple of 3 which is less than 150 is 129.

Answer: D.
_________________
##### Most Helpful Community Reply
CEO  Joined: 20 Nov 2005
Posts: 2542
Schools: Completed at SAID BUSINESS SCHOOL, OXFORD - Class of 2008

### Show Tags

17
11
D

That means H is half of G.
So G+ H = 3H.
This means sum of G and H must be divisible by 3.
C and E are out.

Lets see other choices

A - 153 then H = 51, G = 102 G is a two gidit number
B - 150 then H = 50, G = 100 G is a two gidit number
D - 129 then H = 43, G = 86 ANSWER
_________________
SAID BUSINESS SCHOOL, OXFORD - MBA CLASS OF 2008
##### General Discussion
Director  Joined: 06 May 2006
Posts: 674

### Show Tags

2
1
D it is...

The way to do it is to try and break the units digit into numbers that satisfy the criterion that it should be the sum of a number and its double... i.e. x + 2x...

A satisfies, as 3 = 1 + 2, but 15 cannot be broken into such a form.
The next choice that satisfies is D; 9 = 3 + 6. Also, 12 can be written as (8+4)... Hence D
_________________
Uh uh. I know what you're thinking. "Is the answer A, B, C, D or E?" Well to tell you the truth in all this excitement I kinda lost track myself. But you've gotta ask yourself one question: "Do I feel lucky?" Well, do ya, punk?
VP  Joined: 02 Jun 2006
Posts: 1124

### Show Tags

7
4
D 129

Given G =10x+y
H= 10 (x/2) + y/2

G+H = 3/2(10x+y) = 3/2G

G < 100 => G+H < 150

A & B are ruled out

(G+H)x2/3 = G an integer.

Only D is an integer.

Answer: D
VP  Joined: 14 May 2006
Posts: 1150

### Show Tags

1
Can you enlighten me why not E? what am I missing?

46 and 23 is 89
VP  Joined: 29 Dec 2005
Posts: 1142
Re: PS: sum of 2 digit numbers  [#permalink]

### Show Tags

1
divide each answer choice by 3, the result must be 2 digit number and cannot be greater than 44. also the unit digit of the resulting 2 digit number cannot be greater than 4.

A. 153/3 = 51. no good.
B 150/3 = 50. again not.
C 137/3 = fraction doesnot work.
D 129/3 = 43. it works but let wait for E.
E 89/3 = fraction. same as C.

so, D is the answer.
VP  Joined: 14 May 2006
Posts: 1150
Re: PS: sum of 2 digit numbers  [#permalink]

### Show Tags

Professor wrote:
divide each answer choice by 3, the result must be 2 digit number and cannot be greater than 44. also the unit digit of the resulting 2 digit number cannot be greater than 4.

I am sorry... probably a dumb but please bear with me so, why are we diving these by 3? VP  Joined: 14 May 2006
Posts: 1150

### Show Tags

paddyboy wrote:
u2lover wrote:
Can you enlighten me why not E? what am I missing?

46 and 23 is 89

69, not 89 talking about feeling stupid on some days... can't stop laughing now... I need lunch no carbs VP  Joined: 02 Jun 2006
Posts: 1124

### Show Tags

Eat some fruits... u2lover wrote:
I need lunch no carbs VP  Joined: 29 Dec 2005
Posts: 1142
Re: PS: sum of 2 digit numbers  [#permalink]

### Show Tags

3
u2lover wrote:
Professor wrote:
divide each answer choice by 3, the result must be 2 digit number and cannot be greater than 44. also the unit digit of the resulting 2 digit number cannot be greater than 4.

I am sorry... probably a dumb but please bear with me so, why are we diving these by 3? probably you got it by the time you read this post.

the question says that H is half of G and G is divisible by 2. if so G = 2H
their sum = G + H = 2H + H = 3H

so it should be divisible by 3.
VP  Joined: 29 Dec 2005
Posts: 1142

### Show Tags

haas_mba07 wrote:
Eat some fruits... u2lover wrote:
I need lunch no carbs yup, take some fruit. i just finished 3 bowls cuz i had to divide every answer choice by 3. GMAT Instructor B
Joined: 04 Jul 2006
Posts: 1226
Location: Madrid

### Show Tags

If H has digits x and y, G has digits 2x and 2y.
So G+H =30x+3y and x and y are less than 5

G+H must be a multiple of 3, and units digit must be one of {3,6,9,2}

Unless units digit is 2, number formed by hundreds and tens digits must be a multiple of 3.

Only D fits the bill
Manager  Joined: 08 May 2004
Posts: 156
Location: Pittsburgh

### Show Tags

I got it in 30 seconds by picking numbers
I started out around 80 as the answer choices are about the 120-130 mark..
Current Student Joined: 28 Dec 2004
Posts: 2992
Location: New York City
Schools: Wharton'11 HBS'12

### Show Tags

I remember a trick from last year, someone from kaplan had told me..whenever u see the "which of the following" type question..start with answer choices in the bottom, i.e d and e..

ok, so lets see

i picked answer choice D ...129..hmm...

sum=2X+x....so lets 129=3x, does it divide by 3 yes...x=43....i will keep the answer choice..i check 89..does it divide by 3..NO..so I am done...129 is my answer...
GMAT Instructor B
Joined: 04 Jul 2006
Posts: 1226
Location: Madrid

### Show Tags

As a Kaplan instructor, I can tell you that that advice is not helpful. The correct answer is just as likely to be A as E. You should quickly look at all of the answers to see which is the easiest to evaluate/most promising.
SVP  Joined: 30 Mar 2006
Posts: 1507

### Show Tags

D

let the tens digit be x and units digit be y

Hence first number = 10x + y
Second number = 5x + y/2

Sum = 15x + 3y/2

Substitute values for x and y
15*8 + 3*6/2 = 129
Director  Status: There is always something new !!
Affiliations: PMI,QAI Global,eXampleCG
Joined: 08 May 2009
Posts: 940
Re: odds and evens!  [#permalink]

### Show Tags

the unit digit combinations are 6,3; 8,4; 4,2 giving 9, 2 and 6 as the units digit of the sum.

also if the digits are x and y then G = 10x + y and H = 5x + 0.5y G + H = 1.5 ( 10x + y).

thus with these two criteria. D fits the bill.
Retired Moderator B
Joined: 16 Nov 2010
Posts: 1345
Location: United States (IN)
Concentration: Strategy, Technology
Re: odds and evens!  [#permalink]

### Show Tags

02468 - Even digits

12349 - Odd digits

So the set of halves of even digits gives (odds can't be halved):

01234

86
43
---
129

With some trial and error :

Answer - D
_________________
Formula of Life -> Achievement/Potential = k * Happiness (where k is a constant)

GMAT Club Premium Membership - big benefits and savings
Retired Moderator Joined: 20 Dec 2010
Posts: 1710
Re: odds and evens!  [#permalink]

### Show Tags

AnkitK wrote:
Each digit in the 2 digit number G is halved to form a new 2 digit number H.Which of the following could be the sum of G and H?
A.153
B.150
c.137
D.129
E.89

Say H=xy [x is the ten's place digit after being halved and y is the unit's place digit after being halved]
H=10x+y

G=(2x)(2y)
G=10*(2x)+2y

Possible values of 2x=2,4,6,8; 2y=0,2,4,6,8
Possible values of x=1,2,3,4; y=0,1,2,3,4

G+H=20x+2y+10x+y=30x+3y=3(10x+y)

Thus, the sum must be a multiple of 3; options C and E are out.

Let's try other options:
A. 3(10x+y)=153 i.e. 10x+y=51 i.e. 10*5+1=51; x=5(Not a possible value of x) and y=1
B. 3(10x+y)=150 i.e. 10x+y=50 i.e. 10*5+0=50; x=5(Not a possible value of x) and y=0
D. 3(10x+y)=129 i.e. 10x+y=43 i.e. 10*4+3=43; x=4(Possible) and y=3(Possible)

Ans: D
_________________ Re: odds and evens!   [#permalink] 05 May 2011, 08:35

Go to page    1   2   3    Next  [ 52 posts ]

Display posts from previous: Sort by

# Each digit in the two-digit number G is halved to form a new

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

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

#### MBA Resources  