It is currently 22 Sep 2017, 10:18

### 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 June
Open Detailed Calendar

# Jack is now 14 years older than Bill. If in 10 years Jack

Author Message
TAGS:

### Hide Tags

Manager
Joined: 02 Dec 2012
Posts: 178

Kudos [?]: 3319 [2], given: 0

Jack is now 14 years older than Bill. If in 10 years Jack [#permalink]

### Show Tags

20 Dec 2012, 05:47
2
KUDOS
7
This post was
BOOKMARKED
00:00

Difficulty:

25% (medium)

Question Stats:

73% (01:15) correct 27% (01:34) wrong based on 920 sessions

### HideShow timer Statistics

Jack is now 14 years older than Bill. If in 10 years Jack will be twice as old as Bill, how old will Jack be in 5 years?

(A) 9
(B) 19
(C) 21
(D) 23
(E) 33
[Reveal] Spoiler: OA

Kudos [?]: 3319 [2], given: 0

Math Expert
Joined: 02 Sep 2009
Posts: 41686

Kudos [?]: 124452 [1], given: 12078

Re: Jack is now 14 years older than Bill. If in 10 years Jack [#permalink]

### Show Tags

20 Dec 2012, 05:50
1
KUDOS
Expert's post
1
This post was
BOOKMARKED
Jack is now 14 years older than Bill. If in 10 years Jack will be twice as old as Bill, how old will Jack be in 5 years?

(A) 9
(B) 19
(C) 21
(D) 23
(E) 33

Currently: J = B + 14;
In 10 year: J + 10 = 2(B + 10);

Solving gives J = 18;

Thus in 5 years Jack will be 18 + 5 = 23 years old.

_________________

Kudos [?]: 124452 [1], given: 12078

Manager
Joined: 12 Jan 2013
Posts: 218

Kudos [?]: 76 [0], given: 47

Re: Jack is now 14 years older than Bill. If in 10 years Jack [#permalink]

### Show Tags

10 Jan 2014, 02:57
Jack is now 14 years older than Bill. If in 10 years Jack will be twice as old as Bill, how old will Jack be in 5 years?

(A) 9
(B) 19
(C) 21
(D) 23
(E) 33

Set up the equations: [J = B + 14] and [J + 10 = 2(B + 10)], subtract the two and solve for B, this gives us B = 4.. From the first equation we know that Jack is 14 years older than Bill today, which means that Jack is 14 + 4 = 18 years old.. So naturally, in 5 years he's 23 years old.

Kudos [?]: 76 [0], given: 47

Intern
Joined: 08 Oct 2013
Posts: 1

Kudos [?]: [0], given: 23

Re: Jack is now 14 years older than Bill. If in 10 years Jack [#permalink]

### Show Tags

09 Jun 2014, 14:52
Bunuel wrote:
Jack is now 14 years older than Bill. If in 10 years Jack will be twice as old as Bill, how old will Jack be in 5 years?

(A) 9
(B) 19
(C) 21
(D) 23
(E) 33

Currently: J = B + 14;
In 10 year: J + 10 = 2(B + 10);

Solving gives J = 18;

Thus in 5 years Jack will be 18 + 5 = 23 years old.

We know that J = B + 14

B = J + 14

So to add 10 to both sides, we get

J + 10 = 2 ( B + 14 ) + 10

Why should we have 2 ( B + 10 ) ?

Thanks,

Kudos [?]: [0], given: 23

Math Expert
Joined: 02 Sep 2009
Posts: 41686

Kudos [?]: 124452 [0], given: 12078

Re: Jack is now 14 years older than Bill. If in 10 years Jack [#permalink]

### Show Tags

09 Jun 2014, 15:32
Abraham00 wrote:
Bunuel wrote:
Jack is now 14 years older than Bill. If in 10 years Jack will be twice as old as Bill, how old will Jack be in 5 years?

(A) 9
(B) 19
(C) 21
(D) 23
(E) 33

Currently: J = B + 14;
In 10 year: J + 10 = 2(B + 10);

Solving gives J = 18;

Thus in 5 years Jack will be 18 + 5 = 23 years old.

We know that J = B + 14

B = J + 14

So to add 10 to both sides, we get

J + 10 = 2 ( B + 14 ) + 10

Why should we have 2 ( B + 10 ) ?

Thanks,

First of all, from J = B + 14, we get that B = J - 14, not B = J + 14.

Next, we are told that in 10 years Jack will be twice as old as Bill: in 10 years, Jack will J + 10 years and Bill will be B + 10 years. So, J + 10 = 2(B + 10).

Hope it's clear.
_________________

Kudos [?]: 124452 [0], given: 12078

Current Student
Joined: 12 Jun 2014
Posts: 289

Kudos [?]: 107 [0], given: 79

Location: India
Concentration: General Management, Technology
Schools: Duke '18 (M)
GMAT 1: 740 Q49 V41
WE: Information Technology (Consulting)
Re: Jack is now 14 years older than Bill. If in 10 years Jack [#permalink]

### Show Tags

15 Jul 2014, 12:09
I did this using number substitution. When we set up J=B+14, and we want to know J+5, we can safely say we want B+19 here. Since B cannot be zero, a and b are ruled out. Then you substitute the remaining values, starting from the middle one, which is 23. And you get the answer.

Kudos [?]: 107 [0], given: 79

Intern
Joined: 13 Dec 2013
Posts: 40

Kudos [?]: 19 [1], given: 10

Schools: Fuqua (I), AGSM '16
GMAT 1: 620 Q42 V33
Re: Jack is now 14 years older than Bill. If in 10 years Jack [#permalink]

### Show Tags

22 Aug 2014, 15:11
1
KUDOS
Interpreting the 2nd equation could get tricky.

I recommend using POE. It takes less than 1min.

b) 19 - 5 = Jack is 14 now and and therefore Bill is 0 years old. NEXT

c) 21 - 5 = Jack is 16 and Bill is 2. Then, in 10 years Jack will be 26 and Bill 12. That is not twice the age as stated, so move on to the next one.

d) 23 - 5 = 18 and Bill is 4. Then, in 10 years Jack will be 28 and Bill 14. CORRECT.

Kudos [?]: 19 [1], given: 10

Intern
Joined: 25 Jan 2015
Posts: 1

Kudos [?]: [0], given: 2

Re: Jack is now 14 years older than Bill. If in 10 years Jack [#permalink]

### Show Tags

14 Jun 2015, 17:28
Thinking out the problem conceptually you can solve the problem quite quickly in your head(or paper):

1) If Jack is twice as old as Bill in 10 years then the difference between the two ages(at that time) is equal to Bill's age! Since they are 14 years apart (always), Bill is currently 4 and Jack 18.
2)18+5 = 23 -->(D)

No more than 30 seconds to solve this way

Kudos [?]: [0], given: 2

Optimus Prep Instructor
Joined: 06 Nov 2014
Posts: 1905

Kudos [?]: 516 [1], given: 23

Re: Jack is now 14 years older than Bill. If in 10 years Jack [#permalink]

### Show Tags

17 Jun 2015, 08:31
1
KUDOS
Expert's post
Jack is now 14 years older than Bill. If in 10 years Jack will be twice as old as Bill, how old will Jack be in 5 years?

J+5 = ?
J = B + 14 => B = J - 14
J + 10 = 2 (B + 10) => J + 10 = 2B + 20 => J= 2B + 10
J = 2(J-14) + 10
J = 2J - 28 + 10
J = 2J -18
J = 18
=> 18 + 5
(A) 9
(B) 19
(C) 21
(D) 23
(E) 33
_________________

# Janielle Williams

Customer Support

Special Offer: \$80-100/hr. Online Private Tutoring
GMAT On Demand Course \$299
Free Online Trial Hour

Kudos [?]: 516 [1], given: 23

Target Test Prep Representative
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 1414

Kudos [?]: 760 [1], given: 5

Re: Jack is now 14 years older than Bill. If in 10 years Jack [#permalink]

### Show Tags

23 Jun 2016, 09:36
1
KUDOS
Expert's post
Jack is now 14 years older than Bill. If in 10 years Jack will be twice as old as Bill, how old will Jack be in 5 years?

(A) 9
(B) 19
(C) 21
(D) 23
(E) 33

We first want to create variables for Jack’s age today and Bill’s age today.

J =Jack’s age today

B = Bill’s age today

Now we can use these variables to set up two equations.

We are given that Jack is now 14 years older than Bill. This relationship is represented in our first equation.

J = B + 14  Eq (1)

Next we are given that in 10 years Jack will be twice as old as Bill. Remember, in setting up this equation we must add 10 years to both Jack's and Bill’s current ages, respectively.

10 + J = 2(B + 10)

10 + J = 2B + 20

J = 2B + 10  Eq (2)

Now we can set our two equations (Eq (1) and Eq (2)) equal to each other and determine the value of B.

B + 14 = 2B + 10

B = 4

This means that Bill’s age today is 4.

Thus, we know that Jack’s age today is 14 + 4 = 18.

This means that Jack’s age in 5 years will be 18 + 5 = 23.

_________________

Jeffery Miller

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Kudos [?]: 760 [1], given: 5

GMAT Club Legend
Joined: 09 Sep 2013
Posts: 17591

Kudos [?]: 270 [0], given: 0

Re: Jack is now 14 years older than Bill. If in 10 years Jack [#permalink]

### Show Tags

13 Jul 2017, 04:34
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.
_________________

Kudos [?]: 270 [0], given: 0

Re: Jack is now 14 years older than Bill. If in 10 years Jack   [#permalink] 13 Jul 2017, 04:34
Similar topics Replies Last post
Similar
Topics:
Gita is 12 years older than Harvey. In 4 years, Gita will be twice as 3 16 Aug 2017, 00:25
1 John is 20 years older than Brian. 12 years ago, John was 3 29 Aug 2017, 16:16
1 Jim is now twice as old as Fred, who is two years older than Sam. Four 3 09 Jan 2016, 14:18
2 Tom is 10 years older than Carrie. However, 5 years ago Tom was twice 5 03 Jun 2017, 08:53
23 Roy is now 4 years older than Erik and half of that amount 11 18 Oct 2016, 09:40
Display posts from previous: Sort by