It is currently Sat Apr 17, 2021 2:27 am

 All times are UTC [ DST ]

 Page 1 of 1 [ 9 posts ]
 Print view Previous topic | Next topic
Author Message
 Posted: Fri Jun 10, 2016 6:46 pm

Joined: Fri Jun 10, 2016 6:08 pm
Posts: 3
Place the numbers 1 to 9 inclusive, one each, in these gaps to make this sum correct:

- - - - x 3 = - - - - -

Any help with how to approach this question (and the answer) would be greatly received. There just seem to be too many possible combinations to trial and error this, so I must be missing something!

Top

 Posted: Fri Jun 10, 2016 10:45 pm

Joined: Sat Jul 24, 2010 10:45 pm
Posts: 1586
I haven't had a go at it myself, but the first thing to bear in mind is that the sum of the digits making the answer has to be divisible by 3 (from divisibility rules).

Also, the answer has to be less than 30,000 because 30,000 divided by 3 is a 5-digit number and you need to multiply a 4-digit number by 3 to get a 5-digit number answer. This means that the first digit in the answer cannot be bigger than 2 and that should give you a clue as to what digit the first number may be starting with.

(x-posted with Guest55 )

_________________
It felt like I hit rock bottom; suddenly, there was knocking from beneath... (anon.)

Last edited by PurpleDuck on Fri Jun 10, 2016 10:58 pm, edited 2 times in total.

Top

 Posted: Fri Jun 10, 2016 10:50 pm

Joined: Mon Feb 12, 2007 2:21 pm
Posts: 16254
Start with the units digit on the left - are there some numbers you can eliminate?

Top

 Posted: Fri Jun 10, 2016 10:54 pm

Joined: Wed May 28, 2014 8:38 pm
Posts: 5
5832*3=17496

Top

 Posted: Fri Jun 10, 2016 10:58 pm

Joined: Mon Feb 12, 2007 2:21 pm
Posts: 16254
Sorry - 'see' - what is the point of posting an answer? This does not help the OP at all

Last edited by Guest55 on Fri Jun 10, 2016 11:00 pm, edited 1 time in total.

Top

 Posted: Fri Jun 10, 2016 11:00 pm

Joined: Sat Jul 24, 2010 10:45 pm
Posts: 1586
See - you've just taken away Jaxx's entertainment for the weekend...

_________________
It felt like I hit rock bottom; suddenly, there was knocking from beneath... (anon.)

Top

 Posted: Fri Jun 10, 2016 11:55 pm

Joined: Tue Apr 08, 2014 10:25 pm
Posts: 246
I too got the same answer as above. I focussed on 5 first. Since 5x3=15 and we cannot have two fives, I thought that perhaps 5 was a part of the 4 digit number. It might then have got a carry over of 1 or 2 from the previous number changing the multiplication so that the answer would no longer have a 5 in it. Also it was no use having 51,52 or 53 as they were not providing a carry over of 1 or 2.
51x3=153, 52x3=156, 53x3=159.
So the number after 5 needed to be 4 or more.
example: 54x3=162
Then I wrote down the remaining digits and picked the ones that satisfied the 3x table rule. I inserted them at the end of the 3 digit answer (above) to make it a 5-digit number and see if it worked. From this point it was trial and improvement I am afraid.

It did take me a while. How are the children expected to do this in a short amount of time I wonder.

Top

 Posted: Sat Jun 11, 2016 8:58 pm

Joined: Wed May 28, 2014 8:38 pm
Posts: 5
Its another answer 5823*3=17469 we can inter change 2 and 3 because that multiple 3 have no carry

Top

 Posted: Sat Jun 11, 2016 9:29 pm

Joined: Mon Feb 12, 2007 2:21 pm
Posts: 16254
Please stop posting answers and explain how to tackle the question.

Answers don't help someone tackle a similar question in the future.

Top

 Display posts from previous: All posts1 day7 days2 weeks1 month3 months6 months1 year Sort by AuthorPost timeSubject AscendingDescending
 Page 1 of 1 [ 9 posts ]

 All times are UTC [ DST ]

#### Who is online

Users browsing this forum: No registered users and 10 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    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
Privacy Policy | Refund Policy | Disclaimer | Copyright © 2004 – 2021