Go to navigation
It is currently Sat Dec 03, 2016 5:43 pm

All times are UTC




Post new topic Reply to topic  [ 23 posts ]  Go to page 1, 2, 3  Next
Author Message
 Post subject: maths -number sequence
PostPosted: Sun May 09, 2010 4:19 pm 
Offline

Joined: Wed Dec 09, 2009 12:59 pm
Posts: 11
Pls help, my DD can't work these out. Neither can I!!

1. What is the answer to this nimber sequence
1 2 4 8 10 20 ____ ____ .

Please explain

2. Paul is given a box of 45 chocolates. His brother eats 20%and his mum eats 2/5. How many chocolates are left for Paul?


:D


Top
 Profile  
 
 Post subject:
PostPosted: Sun May 09, 2010 4:31 pm 
Offline

Joined: Tue May 05, 2009 9:26 pm
Posts: 439
Question 2: Answer = 18

20% = 1/5. So 3/5 are eaten ie 27 ( 45 divided by 5 = 9. Then x 3). Therefore 45 - 27 = 18.


Top
 Profile  
 
 Post subject:
PostPosted: Sun May 09, 2010 4:35 pm 
Offline

Joined: Tue May 05, 2009 9:26 pm
Posts: 439
Question 1:

The next two nos are 22 and 44.

THere are two difference alternating sequences here:

1,4 10 22

and

2,8,20 and 44

The difference between the nos in the first sequence doubles, so the differences are 3,6,12

The difference between the nos in the second sequence doubles too, so the differences are 6, 12, 24


Top
 Profile  
 
 Post subject:
PostPosted: Sun May 09, 2010 4:36 pm 
Offline

Joined: Mon Dec 10, 2007 9:55 pm
Posts: 18
Question 1: The pattern is x2, +2 so the next two numbers are 22, 44


Top
 Profile  
 
 Post subject:
PostPosted: Sun May 09, 2010 4:36 pm 
Offline

Joined: Wed Apr 28, 2010 11:19 am
Posts: 294
DD thinks the first one is a leapfrog sequence, ie 2 sequences in one

1..... 4..... 10..... ?
+3 +6 therefore next in sequence is +12 so 1st ? is 22

2..... 8 ..... 20 ..... ?
+6 +12 therefore next in sequence is +24 so 2nd ? is 44


The second problem is...
Paul is given a box of 45 chocolates. His brother eats 20% ie 1/5
and his mum eats 2/5. How many chocolates are left for Paul? so 1/5 + 2/5 = 3/5 have been eaten, this leaves 2/5 of 45 = 18 chocs left for Paul.

_________________
www.TickerFactory.com/weight-loss]
Image


Top
 Profile  
 
 Post subject:
PostPosted: Sun May 09, 2010 4:38 pm 
Offline

Joined: Tue May 05, 2009 9:26 pm
Posts: 439
Gosh how interesting that we have approached question 1 completely differently and got the same answers!


Top
 Profile  
 
 Post subject:
PostPosted: Sun May 09, 2010 6:03 pm 
Offline

Joined: Wed Dec 09, 2009 12:59 pm
Posts: 11
Hi guys,

Thanks for answering so promptly. DD and I understand it now.

:D :D


Top
 Profile  
 
 Post subject:
PostPosted: Mon May 10, 2010 9:29 am 
Offline

Joined: Fri Sep 11, 2009 10:10 am
Posts: 52
I totally understand the approach for Q1 (the number sequence) with answers 22 and 44.It makes complete sense.

But when given this question, one of the answers that came up in the discussion at home was :

1, 2,4,8, 10, 20, 40, 80, 100, 200, 400, 800, 1000, 2000, 4000, 8000 and so on.

In this case, the next two numbers would be 40, 80.
This is a sequence of repetitions. Shouldn't this kind of approach be ever applied for a 11+ Maths ?


Top
 Profile  
 
 Post subject:
PostPosted: Mon May 10, 2010 9:40 am 
Offline

Joined: Tue May 05, 2009 9:26 pm
Posts: 439
I think that there is not sufficient evidence in the string of nos given in the question for that type of approach.


Top
 Profile  
 
 Post subject:
PostPosted: Mon May 10, 2010 10:29 am 
Offline

Joined: Tue Sep 01, 2009 3:38 pm
Posts: 2083
Location: Maidstone
Thats what I thought at first too Abr but then there is 8 to 10 which throws out that sequence.

_________________
Impossible is Nothing.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 23 posts ]  Go to page 1, 2, 3  Next

All times are UTC


Who is online

Users browsing this forum: No registered users and 2 guests


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

Search for:
Jump to:  
CALL 020 8204 5060
   
Privacy Policy | Refund Policy | Disclaimer | Copyright © 2004 – 2016