Last visit was: 25 Apr 2024, 22:42 It is currently 25 Apr 2024, 22:42

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
CEO
CEO
Joined: 29 Jan 2005
Posts: 2887
Own Kudos [?]: 1117 [0]
Given Kudos: 0
Send PM
User avatar
Intern
Intern
Joined: 11 Jul 2005
Posts: 42
Own Kudos [?]: 4 [0]
Given Kudos: 0
Location: New York
Send PM
User avatar
Director
Director
Joined: 24 Sep 2005
Posts: 833
Own Kudos [?]: 1481 [0]
Given Kudos: 0
Send PM
User avatar
Director
Director
Joined: 28 May 2005
Posts: 986
Own Kudos [?]: 3462 [0]
Given Kudos: 0
Location: Dhaka
Send PM
Re: A man has nine children whose ages are at an exact interval. [#permalink]
laxieqv wrote:
well, this problem is somewhat similar to the MGMAT posted by me long time ago ..the trick is to skillfully expression the age of each ...realize that 9 is odd. There's possibly a symmetric point, call it t
we have the age of 9 children are
(t-4a), (t-3a),(t-2a), (t-a), t, (t+a) , (t+2a),(t+3a),(t+4a)

spread the sum of those 9 squares, those t*a will be cancelled mutually.
the rest is:

9t^2+60a^2= D^2 ( D is the father's age)
--->(D-3t)(D+3t)= 60a^2
since they're all integer ...try to find those integers which satisfy the equation.


but the question says A man has nine children whose ages are at an exact interval.

so how does your formula work then?
User avatar
Director
Director
Joined: 24 Sep 2005
Posts: 833
Own Kudos [?]: 1481 [0]
Given Kudos: 0
Send PM
Re: A man has nine children whose ages are at an exact interval. [#permalink]
nakib77 wrote:
laxieqv wrote:
well, this problem is somewhat similar to the MGMAT posted by me long time ago ..the trick is to skillfully expression the age of each ...realize that 9 is odd. There's possibly a symmetric point, call it t
we have the age of 9 children are
(t-4a), (t-3a),(t-2a), (t-a), t, (t+a) , (t+2a),(t+3a),(t+4a)

spread the sum of those 9 squares, those t*a will be cancelled mutually.
the rest is:

9t^2+60a^2= D^2 ( D is the father's age)
--->(D-3t)(D+3t)= 60a^2
since they're all integer ...try to find those integers which satisfy the equation.



but the question says A man has nine children whose ages are at an exact interval.

so how does your formula work then?


the interval is a :wink: ...add a to the smallest, get the next one, add a to the next one, get the next next one and so forth ..check it, buddy :wink:



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
GMAT Club Bot
Re: A man has nine children whose ages are at an exact interval. [#permalink]
Moderators:
Math Expert
92915 posts
Senior Moderator - Masters Forum
3137 posts

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