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

It is currently 19 Aug 2018, 00:39

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

In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago

  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: 47983
In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago  [#permalink]

Show Tags

New post 26 Dec 2014, 08:52
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

87% (01:21) correct 13% (01:59) wrong based on 85 sessions

HideShow timer Statistics

Tough and Tricky questions: Word Problems.



In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago Carolyn was twice as old as Sergio was. How old is Sergio now, in years?

A. 20
B. 24
C. 32
D. 35
E. 40

Kudos for a correct solution.

_________________

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

Manager
Manager
User avatar
Joined: 22 Oct 2014
Posts: 88
Concentration: General Management, Sustainability
GMAT 1: 770 Q50 V45
GPA: 3.8
WE: General Management (Consulting)
Re: In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago  [#permalink]

Show Tags

New post 26 Dec 2014, 09:12
1
Quote:
In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago Carolyn was twice as old as Sergio was. How old is Sergio now, in years?

A. 20
B. 24
C. 32
D. 35
E. 40




C = S + 10
C - 30 = 2 * (S - 30)

We can substitute C in the second equation with the first:

S + 10 - 30 = 2 * (S - 30)
=> S = 40

Answer E
_________________

\(\sqrt{-1}\) \(2^3\) \(\Sigma\) \(\pi\) ... and it was delicious!


Please consider giving +1 Kudos if deserved!

Manager
Manager
avatar
Joined: 21 Aug 2010
Posts: 176
Location: United States
GMAT 1: 700 Q49 V35
GMAT ToolKit User
Re: In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago  [#permalink]

Show Tags

New post 26 Dec 2014, 18:08
Bunuel wrote:

Tough and Tricky questions: Word Problems.



In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago Carolyn was twice as old as Sergio was. How old is Sergio now, in years?

A. 20
B. 24
C. 32
D. 35
E. 40

Kudos for a correct solution.



Sergio Age now = S
Carolin S Age now = C


10 years from now C = S+10 --- (1)

30 Years before (C-30) = 2 (S-30)
C = 2S-30 --(2)

(2) - (1) 0 = S - 40
S = 40

Age of Sergio is 40


Ans E
_________________

-------------------------------------

Director
Director
User avatar
G
Joined: 23 Jan 2013
Posts: 598
Schools: Cambridge'16
Re: In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago  [#permalink]

Show Tags

New post 26 Dec 2014, 23:40
1
Eliminate A and B because age cannot be negative (after subtracting 30)

start from C

Ser: now - 32, 30 years ago - 2, in 10 years - 42

Car: now-34, 30 years ago - 4, in 10 years - 44 (eliminate C)

go D

Ser: now - 35, 30 years ago - 5, in 10 years - 45

Car: now - 40, 30 years ago - 10, in 10 years - 50 (eliminate D)

it is E
Manager
Manager
avatar
Joined: 27 Jan 2013
Posts: 175
Location: United States
Concentration: Entrepreneurship, Marketing
GMAT 1: 730 Q49 V40
GPA: 3.5
WE: Supply Chain Management (Telecommunications)
GMAT ToolKit User
Re: In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago  [#permalink]

Show Tags

New post 27 Dec 2014, 00:30
let sergio's age be S and Carolyn age be C.

Now 10 years from now S will be equal to Carolyn's present age. Hence S+10 =C

30 years earlier Carolyn was twice as old as sergio

hence C-30=2 (s-30) ==> Substituting C=S+10 in this we get

S+10-30 = 2s-60 =>s=40.. hence answer is E.
SVP
SVP
User avatar
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1835
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
Re: In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago  [#permalink]

Show Tags

New post 31 Dec 2014, 21:45
Answer = E. 40

.......................... Sergio ................... Carolyn

Current age ........... x ........................... x+10

30 yrs before ......... x-30 ........................ x-20

Given that 2(x-30) = x-20

x = 40
_________________

Kindly press "+1 Kudos" to appreciate :)

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 47983
Re: In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago  [#permalink]

Show Tags

New post 08 Jan 2015, 09:11
Bunuel wrote:

Tough and Tricky questions: Word Problems.



In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago Carolyn was twice as old as Sergio was. How old is Sergio now, in years?

A. 20
B. 24
C. 32
D. 35
E. 40

Kudos for a correct solution.


OFFICIAL SOLUTION:

(E) Let S = Sergio's current age and C = Carolyn's current age.

First, rewrite the two statements in algebraic form.

The first statement translates into:
S + 10 = C.

The second statement translates into:
C – 30 = 2(S – 30).

Because we now have two equations, we can solve for either of the variables. Substitute S + 10 in the first equation for C in the second, and solve:
(S + 10) – 30 = 2(S – 30)
S – 20 = 2S – 60,
S + 40 = 2S
S = 40.

The correct answer is choice (E).
_________________

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

SVP
SVP
User avatar
D
Joined: 26 Mar 2013
Posts: 1783
Reviews Badge CAT Tests
Re: In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago  [#permalink]

Show Tags

New post 20 Mar 2018, 16:17
Bunuel wrote:

Tough and Tricky questions: Word Problems.



In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago Carolyn was twice as old as Sergio was. How old is Sergio now, in years?

A. 20
B. 24
C. 32
D. 35
E. 40

Kudos for a correct solution.


organizing thoughts is key

Now

Sergio age = S
Carolyn = C

After 10 years

Sergio age = S+ 10
Carolyn = C+10

Before 30 years

Sergio age = S - 30
Carolyn = C - 30

Setting up equation:

S +10 = C.....................1

C -30 = 2 (S -30)...........2

From 1 in 2

S + 10 -30 = 2S -60

S = 40

Answer: E
Re: In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago &nbs [#permalink] 20 Mar 2018, 16:17
Display posts from previous: Sort by

In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago

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

Events & Promotions

PREV
NEXT


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®.