Mr. and Mrs. Wiley have a child every J years. Their oldest : GMAT Problem Solving (PS)
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 23 Jan 2017, 08:11

### 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

# Mr. and Mrs. Wiley have a child every J years. Their oldest

Author Message
TAGS:

### Hide Tags

Manager
Joined: 14 Apr 2003
Posts: 84
Followers: 1

Kudos [?]: 22 [1] , given: 0

Mr. and Mrs. Wiley have a child every J years. Their oldest [#permalink]

### Show Tags

19 Feb 2007, 11:40
1
KUDOS
20
This post was
BOOKMARKED
00:00

Difficulty:

45% (medium)

Question Stats:

63% (02:39) correct 37% (01:48) wrong based on 567 sessions

### HideShow timer Statistics

Mr. and Mrs. Wiley have a child every J years. Their oldest child is now T years old. If they have a child 2 years from now, how many children will they have in total?

(A) $$\frac{T+2}{J} + 1$$

(B) $$JT + 1$$

(C) $$\frac{J}{T} + \frac{1}{T}$$

(D) $$TJ - 1$$

(E) $$\frac{T+J}{J}$$

Source: Manhattan Guide
[Reveal] Spoiler: OA
Intern
Joined: 04 Apr 2006
Posts: 35
Followers: 0

Kudos [?]: 5 [0], given: 0

Re: Mr. and Mrs. Wiley have a child every J years. Their oldest [#permalink]

### Show Tags

19 Feb 2007, 14:04
jainvineet wrote:
Mr. and Mrs. Wiley have a child every J years. Their oldest child is now T years old. If they have a child 2 years from now, how many children will they have in total?

1) (T+2)/J + 1
2) JT + 1
3) J/T + 1/T
4) TJ-1
5) (J+T)/J

My answer is (T+2J) /J OA is 1.

Try with numbers:

They have a child every 3 years (J=3)

child 1 is 1 year old
ch 2 4y
ch 3 7y
ch 4 10y (oldest)

T=10
They have 4 children now

(10+2)/3 =(T+2)/J

After 2 years they will have (T+2)/J +1
Manager
Joined: 14 Apr 2003
Posts: 84
Followers: 1

Kudos [?]: 22 [0], given: 0

Re: Mr. and Mrs. Wiley have a child every J years. Their oldest [#permalink]

### Show Tags

19 Feb 2007, 17:56
jvujuc wrote:
jainvineet wrote:
Mr. and Mrs. Wiley have a child every J years. Their oldest child is now T years old. If they have a child 2 years from now, how many children will they have in total?

1) (T+2)/J + 1
2) JT + 1
3) J/T + 1/T
4) TJ-1
5) (J+T)/J

My answer is (T+2J) /J OA is 1.

Try with numbers:

They have a child every 3 years (J=3)

child 1 is 1 year old
ch 2 4y
ch 3 7y
ch 4 10y (oldest)

T=10
They have 4 children now

(10+2)/3 =(T+2)/J

After 2 years they will have (T+2)/J +1

Please show me without number substituion.

Ok finally I am able to understand this question.

Age of the oldest kid at the time of birth of latest sibling is (x-1)J where x is the total number of kids.

T+2 = (x-1)J

Hence A. Not so QED.
Senior Manager
Joined: 22 Dec 2009
Posts: 362
Followers: 11

Kudos [?]: 378 [1] , given: 47

Re: Mr. and Mrs. Wiley have a child every J years. Their oldest [#permalink]

### Show Tags

06 Feb 2010, 12:17
1
KUDOS
5
This post was
BOOKMARKED
Mr. and Mrs. Wiley have a child every J years. Their oldest child is now T years old. If they have a child 2 years from now, how many children will they have in total?

(A) $$\frac{T+2}{J} + 1$$

(B) $$JT + 1$$

(C) $$\frac{J}{T} + \frac{1}{T}$$

(D) $$TJ - 1$$

(E) $$\frac{T+J}{J}$$

Source: Manhattan Guide

_________________

Cheers!
JT...........
If u like my post..... payback in Kudos!!

|For CR refer Powerscore CR Bible|For SC refer Manhattan SC Guide|

~~Better Burn Out... Than Fade Away~~

Last edited by Bunuel on 22 Nov 2012, 04:41, edited 1 time in total.
Renamed the topic and edited the question.
Senior Manager
Joined: 25 Jun 2009
Posts: 306
Followers: 2

Kudos [?]: 120 [1] , given: 6

Re: Mr. and Mrs. Wiley have a child every J years. Their oldest [#permalink]

### Show Tags

06 Feb 2010, 12:35
1
KUDOS
2
This post was
BOOKMARKED
jeeteshsingh wrote:
Need the solution using Algebra....

Mr. & Mrs Wiley have a child every J years. Their oldest child is now T years old. If they have a child 2 years from now, how many children will they have in total?

(A) $$\frac{T+2}{J} + 1$$

(B) $$JT + 1$$

(C) $$\frac{J}{T} + \frac{1}{T}$$

(D) $$TJ - 1$$

(E) $$\frac{T+J}{J}$$

[Reveal] Spoiler: OA:
(A)

Source: Manhattan Guide

Lets take it this way,

They had first child today, after J years they will have 2nd child, and again after J years they will have 3rd child..

And now according to the Q stem in T + 2 years they will have J kids

Hence number kids in T + 2 years = T+2 /J

We will have to add 1 (their first/oldest Kid)

Hence Total number of kids = (T+2 / J) + 1

cheers
Senior Manager
Joined: 21 Jul 2009
Posts: 366
Schools: LBS, INSEAD, IMD, ISB - Anything with just 1 yr program.
Followers: 18

Kudos [?]: 164 [1] , given: 22

Re: Mr. and Mrs. Wiley have a child every J years. Their oldest [#permalink]

### Show Tags

06 Feb 2010, 15:05
1
KUDOS
Their oldest kid is T y/o.
From the question stem, their youngest kid alive is J-2 y/o.
We need to know how many kids are there between T and J-2 spaced exactly J years apart. This is an arithmetic progression.

(J-2) + (n-1)J = T, inclusive. This gives n = (T+2)/J. Question stem also states that they are going to have a baby after 2 yrs from now, so we have to add that kid to n to get the total number of kids the Wiley family will have.
_________________

I am AWESOME and it's gonna be LEGENDARY!!!

Intern
Joined: 17 Nov 2009
Posts: 37
Schools: University of Toronto, Mcgill, Queens
Followers: 0

Kudos [?]: 96 [0], given: 9

Re: Mr. and Mrs. Wiley have a child every J years. Their oldest [#permalink]

### Show Tags

13 Feb 2010, 00:21
BarneyStinson wrote:
Their oldest kid is T y/o.
From the question stem, their youngest kid alive is J-2 y/o.
We need to know how many kids are there between T and J-2 spaced exactly J years apart. This is an arithmetic progression.

(J-2) + (n-1)J = T, inclusive. This gives n = (T+2)/J. Question stem also states that they are going to have a baby after 2 yrs from now, so we have to add that kid to n to get the total number of kids the Wiley family will have.

Hi Barney,

Your solution makes sense as its simple AP you applied, but I failed to comprehend that how you get J-2 as first element.

As Q says that they'll have kids after every J years and their oldest kid is T years old and the next kid will be due after two years from now but we don't know that how many years back first kid was born....may be I didn't get rightly.

Cheers!
_________________

--Action is the foundational key to all success.

CEO
Status: Nothing comes easy: neither do I want.
Joined: 12 Oct 2009
Posts: 2795
Location: Malaysia
Concentration: Technology, Entrepreneurship
Schools: ISB '15 (M)
GMAT 1: 670 Q49 V31
GMAT 2: 710 Q50 V35
Followers: 226

Kudos [?]: 1622 [1] , given: 235

Re: Mr. and Mrs. Wiley have a child every J years. Their oldest [#permalink]

### Show Tags

13 Feb 2010, 01:03
1
KUDOS
Ans A

their first child was born after J years...

thus 1 child ---> j years

=> thus after another J years his age = J

thus his age is J --> after 2J years and 2j after 3j years

his present age is T which is after T years.

thus total time after 2years will be T+2
since after every J year they have a child after T+2 they will have $$\frac{(T+2)}{J}$$ + 1 ( +1 is for the oldest)

thus A
_________________

Fight for your dreams :For all those who fear from Verbal- lets give it a fight

Money Saved is the Money Earned

Jo Bole So Nihaal , Sat Shri Akaal

GMAT Club Premium Membership - big benefits and savings

Gmat test review :
http://gmatclub.com/forum/670-to-710-a-long-journey-without-destination-still-happy-141642.html

Manager
Joined: 08 Jun 2011
Posts: 98
Followers: 1

Kudos [?]: 45 [0], given: 65

Re: Mr. and Mrs. Wiley have a child every J years. Their oldest [#permalink]

### Show Tags

02 Nov 2011, 10:08
Sorry for pumping this old one up but I seem to never get it working when J =5 and T =20.

If they have a child every 5 years and their oldest is 20 years then this means that they have
1 child at year 0
2 children at year 5
3 children at year 10
4 children at year 15
5 children at year 20
They have 5 total children right now. After two years, they should have a total of 6.

If I plug in numbers, none of the choices fit.

The answer provided is (A) but if I plug in T + 2 /J + 1 I end up having a non integer.

20 + 2 /5 +1 = 4.5

Any help?
Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 7130
Location: Pune, India
Followers: 2140

Kudos [?]: 13704 [2] , given: 222

Re: Mr. and Mrs. Wiley have a child every J years. Their oldest [#permalink]

### Show Tags

03 Nov 2011, 02:15
2
KUDOS
Expert's post
1
This post was
BOOKMARKED
Sorry for pumping this old one up but I seem to never get it working when J =5 and T =20.

If they have a child every 5 years and their oldest is 20 years then this means that they have
1 child at year 0
2 children at year 5
3 children at year 10
4 children at year 15
5 children at year 20
They have 5 total children right now. After two years, they should have a total of 6.

If I plug in numbers, none of the choices fit.

The answer provided is (A) but if I plug in T + 2 /J + 1 I end up having a non integer.

20 + 2 /5 +1 = 4.5

Any help?

The numbers you chose are incorrect. If J = 5, T cannot be 20 because they are going to have another child in 2 yrs. Hence T can be 23 or 28 etc but not 20.
If T = 23 and J = 5,

T + 2 /J + 1 = (23 + 2)/5 + 1 = 6 which is correct

Think of it this way:

After 2 yrs, there will be another child. If they have a child every J years, it means (J - 2) yrs have passed since they had their last child.
Let's say T = (J-2) + nJ
n is the number of periods of J years that have passed since T was born. In each one of these periods, one child must have been born.

Re-arranging, n = (T+2)/J - 1
so total number of children the couple will have after 2 yrs is n+2 (+2 to account for T and for the child that will be born 2 yrs from now)

Total number of children = (T+2)/J - 1 + 2 = (T+2)/J + 1
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for $199 Veritas Prep Reviews Manager Joined: 08 Jun 2011 Posts: 98 Followers: 1 Kudos [?]: 45 [0], given: 65 Re: Mr. and Mrs. Wiley have a child every J years. Their oldest [#permalink] ### Show Tags 03 Nov 2011, 03:01 VeritasPrepKarishma wrote: Lstadt wrote: Sorry for pumping this old one up but I seem to never get it working when J =5 and T =20. If they have a child every 5 years and their oldest is 20 years then this means that they have 1 child at year 0 2 children at year 5 3 children at year 10 4 children at year 15 5 children at year 20 They have 5 total children right now. After two years, they should have a total of 6. If I plug in numbers, none of the choices fit. The answer provided is (A) but if I plug in T + 2 /J + 1 I end up having a non integer. 20 + 2 /5 +1 = 4.5 Any help? The numbers you chose are incorrect. If J = 5, T cannot be 20 because they are going to have another child in 2 yrs. Hence T can be 23 or 28 etc but not 20. If T = 23 and J = 5, T + 2 /J + 1 = (23 + 2)/5 + 1 = 6 which is correct Think of it this way: After 2 yrs, there will be another child. If they have a child every J years, it means (J - 2) yrs have passed since they had their last child. Let's say T = (J-2) + nJ n is the number of periods of J years that have passed since T was born. In each one of these periods, one child must have been born. Re-arranging, n = (T+2)/J - 1 so total number of children the couple will have after 2 yrs is n+2 (+2 to account for T and for the child that will be born 2 yrs from now) Total number of children = (T+2)/J - 1 + 2 = (T+2)/J + 1 Thank you very much. Please bear with me for a minute. I am still confused as how landed at 23 or 28. Did you choose these numbers to make sure that they end up being divisible by J? Since we must have an integer as the number of children? Veritas Prep GMAT Instructor Joined: 16 Oct 2010 Posts: 7130 Location: Pune, India Followers: 2140 Kudos [?]: 13704 [1] , given: 222 Re: Mr. and Mrs. Wiley have a child every J years. Their oldest [#permalink] ### Show Tags 03 Nov 2011, 23:18 1 This post received KUDOS Expert's post Lstadt wrote: Thank you very much. Please bear with me for a minute. I am still confused as how landed at 23 or 28. Did you choose these numbers to make sure that they end up being divisible by J? Since we must have an integer as the number of children? You chose J as 5. I only picked some values for T that would work with J = 5 How did I do that? After 2 yrs, there will be another child. It means 3 yrs have passed since their last child (since J = 5). If T was born in year 0, there would have been a child every 5 years. Right now, we are 3 yrs more than some multiple of 5. So T could be 3 yrs old (no child born after T)/8 yrs old (1 child born after T)/13 yrs old (2 children born after T) etc _________________ Karishma Veritas Prep | GMAT Instructor My Blog Get started with Veritas Prep GMAT On Demand for$199

Veritas Prep Reviews

Manager
Joined: 08 Jun 2011
Posts: 98
Followers: 1

Kudos [?]: 45 [0], given: 65

Re: Mr. and Mrs. Wiley have a child every J years. Their oldest [#permalink]

### Show Tags

04 Nov 2011, 09:14
VeritasPrepKarishma wrote:
Thank you very much.

Please bear with me for a minute. I am still confused as how landed at 23 or 28. Did you choose these numbers to make sure that they end up being divisible by J? Since we must have an integer as the number of children?

You chose J as 5. I only picked some values for T that would work with J = 5
How did I do that? After 2 yrs, there will be another child. It means 3 yrs have passed since their last child (since J = 5).
If T was born in year 0, there would have been a child every 5 years. Right now, we are 3 yrs more than some multiple of 5. So T could be 3 yrs old (no child born after T)/8 yrs old (1 child born after T)/13 yrs old (2 children born after T) etc

Thank you so much. I now understand it.

To me, it seems as though the wording of the problem is quite obscure because when the question says "They will have a child after two years, it didn't specify whether these two years are included in J or they are just some arbitrary years. That is, they suddenly decided to change their plan and up had a child two years after their last one.
Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 7130
Location: Pune, India
Followers: 2140

Kudos [?]: 13704 [1] , given: 222

Re: Mr. and Mrs. Wiley have a child every J years. Their oldest [#permalink]

### Show Tags

21 Nov 2012, 09:45
1
KUDOS
Expert's post
5
This post was
BOOKMARKED
jeeteshsingh wrote:
Need the solution using Algebra....

Mr. & Mrs Wiley have a child every J years. Their oldest child is now T years old. If they have a child 2 years from now, how many children will they have in total?

(A) $$\frac{T+2}{J} + 1$$

(B) $$JT + 1$$

(C) $$\frac{J}{T} + \frac{1}{T}$$

(D) $$TJ - 1$$

(E) $$\frac{T+J}{J}$$

[Reveal] Spoiler: OA:
(A)

Source: Manhattan Guide

Think of it as an Arithmetic Progression where every subsequent term (child) has a difference of J yrs from the previous term (child).

1st child, 2nd child, 3rd child, ....... nth child (to be born after 2 yrs)

What is the difference between first and last terms (children)? (T + 2) yrs

What is the common difference (age difference between two consecutive kids)? J yrs

What is the number of terms (children)? (T + 2)/J + 1
(Number of terms of an AP is n = (Last term - First term)/Common Difference + 1. )
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for \$199

Veritas Prep Reviews

GMAT Club Legend
Joined: 09 Sep 2013
Posts: 13516
Followers: 577

Kudos [?]: 163 [0], given: 0

Re: Mr. and Mrs. Wiley have a child every J years. Their oldest [#permalink]

### Show Tags

31 Oct 2014, 22:33
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.
_________________
GMAT Club Legend
Joined: 09 Sep 2013
Posts: 13516
Followers: 577

Kudos [?]: 163 [0], given: 0

Re: Mr. and Mrs. Wiley have a child every J years. Their oldest [#permalink]

### Show Tags

29 May 2015, 21:58
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.
_________________
GMAT Club Legend
Joined: 09 Sep 2013
Posts: 13516
Followers: 577

Kudos [?]: 163 [0], given: 0

Re: Mr. and Mrs. Wiley have a child every J years. Their oldest [#permalink]

### Show Tags

27 Jun 2016, 20:01
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.
_________________
Re: Mr. and Mrs. Wiley have a child every J years. Their oldest   [#permalink] 27 Jun 2016, 20:01
Similar topics Replies Last post
Similar
Topics:
3 In a certain law firm, Mr. Jones schedules meetings every 15 minutes, 2 30 Nov 2016, 01:51
2 Mr Ben leaves his house for work at exactly 8:00 AM every mo 6 11 Sep 2013, 01:23
9 During the four years that Mrs. Lopez owned her car, she fou 13 16 Jul 2013, 17:15
9 Mr. Evans will states that each of his children will receive 7 16 Nov 2010, 00:26
A family has a child every j years.  The oldest child is t years old. 1 10 Aug 2010, 14:40
Display posts from previous: Sort by