It is currently Sun Dec 04, 2016 2:04 am

 All times are UTC

 Page 1 of 1 [ 5 posts ]
 Print view Previous topic | Next topic
Author Message
 Post subject: Habs maths 2011 - question 30 can't do itPosted: Sat Dec 10, 2011 7:42 am

Joined: Sun Jul 18, 2010 8:02 pm
Posts: 86
square is 3 units long with 4 identical semi-circles drawn on each edge. semi-circles overlap to create 4 petals which are shaded

the area of each semi-circle is 3.5 square units. work out shaded area

sorry can't draw

Top

 Post subject: Re: Habs maths 2011 - question 30 can't do itPosted: Sat Dec 10, 2011 7:59 am

Joined: Wed Oct 19, 2011 9:18 pm
Posts: 20
Area of Square = 3 X 3 = 9 square units
Total Area of all semi Circles = 3.5 X 4 = 14 square units

So, Area of shaded portions = 14 - 9 = 5 square units

Top

 Post subject: Re: Habs maths 2011 - question 30 can't do itPosted: Sat Dec 10, 2011 9:31 am

Joined: Sun Jul 18, 2010 8:02 pm
Posts: 86

i know i did not draw it but i don't think this is correct

am i wrong twice

Top

 Post subject: Re: Habs maths 2011 - question 30 can't do itPosted: Sat Dec 10, 2011 7:43 pm

Joined: Sat Jul 31, 2010 3:31 pm
Posts: 132
Hi Minesh!

I just looked at the diagram (on Habs web site) until I noticed that I could calculate the unshaded area in this way:

Look at two opposing semi circles and imagine them completely shaded. Their area total 3.5 x 2 =7. What's left? It's the two bits opposite each other, which must total 9 - 7 = 2 in area.

There are two of these unshaded pairs of shapes, so the total unshaded area is 2 x 2 = 4.

So the shaded area of the petals must be 9 - 4 = 5 sq units.

Different approach, but I agree with the previously posted answer.

By the way, I wonder if even the Scholarship winners will get this! I think I was just lucky to see the solution visually quite quickly today!

WH

Top

 Post subject: Re: Habs maths 2011 - question 30 can't do itPosted: Sat Dec 10, 2011 9:14 pm

Joined: Sun Jul 18, 2010 8:02 pm
Posts: 86
Your name is befitting - you work hard

thank you very much for taking the trouble to look at diagram and for clear explanation

Top

 Display posts from previous: All posts1 day7 days2 weeks1 month3 months6 months1 year Sort by AuthorPost timeSubject AscendingDescending
 Page 1 of 1 [ 5 posts ]

 All times are UTC

#### Who is online

Users browsing this forum: No registered users and 4 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