Susan Daughtrey Pack 1 Test 3 q71

Advice on 11 Plus VR papers and problems

Moderators: Section Moderators, Forum Moderators

Post Reply
11 Plus Platform - Online Practice Makes Perfect - Try Now
Josa
Posts: 224
Joined: Mon Apr 28, 2008 10:57 am

Susan Daughtrey Pack 1 Test 3 q71

Post by Josa »

Can someone please help with the sum below, dS is demanding a mark for the question as he thinks there are two answers to it. :roll:


(15[32]2 ) (14[30]2)
(12[?]4)

Answer is 28 but ds thinks it can also be 26
Is there a technique to working out the correct answer?

Thank you
turtleglos
Posts: 455
Joined: Wed Jul 07, 2010 12:04 pm

Re: Susan Daughtrey Pack 1 Test 3 q71

Post by turtleglos »

(15[32]2 ) (14[30]2)
(12[?]4)
(15x2)+2=32
(14x2)+2=30
(12x2)+4=28
How does your ds get to 26?
Everyone is a genius, but if you judge a fish by its ability to climb a tree, it will think it is stupid.
Josa
Posts: 224
Joined: Mon Apr 28, 2008 10:57 am

Re: Susan Daughtrey Pack 1 Test 3 q71

Post by Josa »

Hi turtleglos

DS thought he should be adding 2 each time instead of the number on the right.

Many thanks
First-timer
Posts: 698
Joined: Wed Sep 23, 2009 1:47 pm
Location: Essex

Re: Susan Daughtrey Pack 1 Test 3 q71

Post by First-timer »

Couldn't it also be 52? Product of the two outside numbers plus the number to the right.
turtleglos
Posts: 455
Joined: Wed Jul 07, 2010 12:04 pm

Re: Susan Daughtrey Pack 1 Test 3 q71

Post by turtleglos »

Couldn't it also be 52? Product of the two outside numbers plus the number to the right.
Couldn't it also be 52? Product of the two outside numbers plus the number to the right.
It could, but I would guess that that is not an option in the multiple choice.
Everyone is a genius, but if you judge a fish by its ability to climb a tree, it will think it is stupid.
burcu
Posts: 7
Joined: Fri Nov 13, 2009 6:39 pm

Re: Susan Daughtrey Pack 1 Test 3 q71

Post by burcu »

Hi Josa. The instructions for this type of question in the SD papers state that "The three numbers in each group are related in the same way". I believe that your son's alternative answer does not use one of the numbers in the group for the final group? I would say his answer is therefore incorrect. It is my understanding that you must include both numbers outside the brackets for these types of questions.

As an aside however, when I first looked this up I used the Tutors papers as an example, and their instructions are "In these questions, the middle number in the last group is made up in the same way as the middle number in the first two groups". In this case I would argue that your son's answer would be allowable - but it is not the standard approach and I would not encourage it.
sgcmum
Posts: 182
Joined: Sat Oct 09, 2010 11:46 am

Re: Susan Daughtrey Pack 1 Test 3 q71

Post by sgcmum »

hi turtleglos,
dd chose 28 as the answer when she was doing it as a multiple choice paper but gave 52 as the answer when i gave it as part of a standard test!

sgcmum.
moved
Posts: 3826
Joined: Fri Oct 12, 2007 1:42 pm
Location: Chelmsford and pleased

Re: Susan Daughtrey Pack 1 Test 3 q71

Post by moved »

52 was my first thought too, but 28 is equally valid.
26 cannot work as the 4 has not been used from the second set, but a totally reasonable error.
patricia
Posts: 2803
Joined: Mon Jan 30, 2006 5:07 pm

Re: Susan Daughtrey Pack 1 Test 3 q71

Post by patricia »

15[32]2 ) (14[30]2)
(12[?]4)

There are three credible answers to this question. Fortunately only one of the answers appears on the answer sheet. This question therefore should never be used in standard format.

15 x 2 = 30
30 plus 2 = 32

14 x 2 = 28
28 plus 2 = 30

12 x 4 = 48
48 plus 2 = 50

or:

15 plus 2 =17
17 plus the number on the left = 32

14 plus 2 = 16
16 plus the number on the left = 30

12 plus 4 = 16
16 plus the number on the left = 28

or

15 x 2 = 30
30 plus the number on the right = 32

14 x 2 = 28
28 plus the number on the right = 30

12 x 4 = 48
48 plus the number on the right = 52


Patricia
Post Reply