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NFER VR QUESTION TEST 11 B QUESTION 22 PLEASE HELP!

Posted: Sat Oct 03, 2009 11:46 am
by INONOTHING
Hi all

I hope you can help me with the following question to be found on the NFER multiple choice verbal reasoning paper 11B.

I don't understand how you work out the answer and therefore don't know how to explain it to my daughter.

David, Gemma, Jane, John and Maria are 12, 11, 10, 10 and 9 years old, but not in that order.
David is 2 years younger than John.
Gemma is 2 years younger than Jane.
Maria is older than David.
Who are the twins?

A David and Maria
B John and Jane
C Gemma and David
D Maria and Gemma
E John and Maria

The answer is D - Maria and Gemma

Can anyone please explain how you work this question out and the best and quickest way to explain to DD.

Many thanks for any help
INONOTHING

Posted: Sat Oct 03, 2009 12:18 pm
by heartmum
You know that David is 2yrs younger than John (so at this point is either 9 or 10) and John either 11 or 12. You know Gemma is 2yrs younger than Jane (so either 9 or 10) and Jane either 11 or 12. However, as Maria is older than David she can only be 10 as Jane or John are either 11 or 12. Therefore making David 9 yrs. so ...

John is 11 yrs
Jane is 12 yrs
Maria is 10 yrs (twin)
David is 9 yrs
Gemma is 10 yrs (twin)

Hope this helps? (although with my explanation maybe not :!: )

Posted: Sat Oct 03, 2009 5:52 pm
by Y
This is why you leave this type of question till last...

Sometimes with these, you can do it by a process of trial and error, if you can't manage heartmum's logical thinking. Write out what you do know in a visual form:

=========== John ================== Jane ====


Maria


=========== David ================= Gemma===

That is, you know John is older than David, (by 2 years), you know Jane is older than Gemma (by 2 years), and you know Maria is older than David, but not by how much.
You know the list of ages 12, 11, 10, 10, and 9.
So pick one of Jane or John to be 12, and write that next to Jane's name, and cross 12 off the list.
If Jane is 12, then Gemma is 10. Cross 10 off the list.
That leaves 11, 10 and 9 on the list.
If there are two years between John and David, then they must be 11 and 9, leaving Maria as 10. So Maria and Gemma are the twins.

If you'd picked John as the 12 year old, then the numbers wouldn't work out, because David and Maria end up the same age... (Try it)

These things look even more difficult when you try to explain them in writing, but personally, I can only do them if lay them out visually. Otherwise, the logic defeats me!

Posted: Sat Oct 03, 2009 8:47 pm
by patricia
David, Gemma, Jane, John and Maria are 12, 11, 10, 10 and 9 years old, but not in that order.
David is 2 years younger than John.
Gemma is 2 years younger than Jane.
Maria is older than David.
Who are the twins?

I use 2 columns:

D......10……9

G…....9………10

Ja……11……12

Jo…...12…..11

M…….10……10

First column is incorrect as Maria is the same age as David. 2nd column must be correct as Maria is older than David.

Patricia

Posted: Sat Oct 03, 2009 11:22 pm
by yoyo123
as i have said ( on many an occasion) I swear by a diagram!

Posted: Sun Oct 04, 2009 9:21 am
by patricia
Absolutely YoYo.

I insist on diagrams/tables for Z questions.

In addition, as Y has stated they must be left till last, question number ringed, guessed on the answer sheet and move on. Thats guessing without looking at the contents of the question.

Patricia