It is currently Tue Jan 16, 2018 9:39 am

 All times are UTC

 Page 1 of 1 [ 6 posts ]
 Print view Previous topic | Next topic
Author Message
 Post subject: Help with VRPosted: Tue Jun 07, 2011 5:29 pm

Joined: Tue Jun 07, 2011 12:37 pm
Posts: 14
Can anyone tell me how to approach the following style question:

Use three of the numbers on the left once only to make up the number you are given.

7,9,11,13,16 : 31= ( + + )

My daughter didn't know where to start with these - are there any techniques I can tell her to use?

Top

 Post subject: Re: Help with VRPosted: Tue Jun 07, 2011 5:35 pm

Joined: Mon Jun 18, 2007 2:32 pm
Posts: 7137
Location: East Kent
I would try trial and error to begin with.
16 + 13 = 29 ..can;t be those two as there is no 2 etc. afetr a while she will get a feel for which numbers are likely. Lots of practice.

I haven;t seen examples like this before.

Where are you based?
Is this a multiple choice question or standard?

Top

 Post subject: Re: Help with VRPosted: Tue Jun 07, 2011 5:46 pm

Joined: Tue Jun 07, 2011 12:37 pm
Posts: 14
We live in Lincolnshire. It is standard format and so can be very time consuming! I haven't seen many of these type of questions either, maybe they are just specific to Lincs. Maths is not my daughter's strong point which is why I'm a bit worried.

Top

 Post subject: Re: Help with VRPosted: Tue Jun 07, 2011 6:05 pm

Joined: Fri Nov 17, 2006 8:54 pm
Posts: 1776
Location: caversham
Have a look at the Susan J. Daughtrey method & technique books.

Quote:
Books 1, 2, 3 and 4 cover the TECHNIQUE and PRACTICE of each of the 35 Types of question. Book 1 covers the first 13 Types, book 2 covers 10 Types and the remaining Types are dealt with in books 3 and 4 deals specifically with maths and code questions.

http://www.elevenplusexams.co.uk/books/list.php?g=f&p=7
.

Top

 Post subject: Re: Help with VRPosted: Tue Jun 07, 2011 6:38 pm

Joined: Sat Feb 13, 2010 11:02 pm
Posts: 420
staffakh wrote:
Can anyone tell me how to approach the following style question:

Use three of the numbers on the left once only to make up the number you are given.

7,9,11,13,16 : 31= ( + + )

hi,

I have not come across this type of question before, but I would suggest that you take one number away from the 31 and then see if the remainder can be made by two of the other numbers.

eg, 31-7 = 24, can 24 be made by two others?

31- 9= 22, can 22 be made by two others?

31- 11= 20, can 20 be made by two others? 7+13 = 20

so the answer is 7+13+11 (I think!)

Top

 Post subject: Re: Help with VRPosted: Thu Jun 09, 2011 3:47 pm

Joined: Thu Oct 21, 2010 4:38 pm
Posts: 109
The question "which numbers from this list add up to this number?" turns out to be, in general, extremely hard and very interesting. It's nice to have a problem which is simple enough, in a small example, to make an 11+ question, but leads on to some fairly challenging (undergraduate, or possibly just on the outer limits of A Level) theory by just adding some more numbers to the question.

Suppose I gave you a hundred numbers and asked you to choose the ones that added up to some other number. How long did it take you? Now, suppose I give you a thousand numbers and give you ten times longer than it took with a hundred numbers. Can you do it?

Manage that and you're well on your way to a million dollars. No, really, a million dollars.

http://www.claymath.org/millennium/P_vs_NP/

http://en.wikipedia.org/wiki/Subset_sum_problem

Top

 Display posts from previous: All posts1 day7 days2 weeks1 month3 months6 months1 year Sort by AuthorPost timeSubject AscendingDescending
 Page 1 of 1 [ 6 posts ]

 All times are UTC

#### Who is online

Users browsing this forum: No registered users and 2 guests

 You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forumYou cannot post attachments in this forum

Search for:
 Jump to:  Select a forum ------------------ FORUM RULES    Forum Rules and FAQs 11 PLUS SUBJECTS    VERBAL REASONING    MATHS    ENGLISH    NON-VERBAL REASONING    CEM 11 Plus GENERAL    GENERAL 11 PLUS TOPICS    11 PLUS APPEALS    11 PLUS TUTORS    INDEPENDENT SCHOOLS    11 PLUS CDs/SOFTWARE    11 PLUS TIPS    PRIMARY    SEN and the 11 PLUS    EVERYTHING ELSE .... 11 PLUS REGIONS    Berkshire    Bexley and Bromley    Birmingham, Walsall, Wolverhampton and Wrekin    Buckinghamshire    Devon    Dorset    Essex    Essex - Redbridge    Gloucestershire    Hertfordshire (South West)    Hertfordshire (Other and North London)    Kent    Lancashire & Cumbria    Lincolnshire    Medway    Northern Ireland    Surrey (Sutton, Kingston and Wandsworth)    Trafford    Warwickshire    Wiltshire    Wirral    Yorkshire BEYOND 11 PLUS    Beyond 11 Plus - General    GCSEs    6th Form    University