Answer to a type 19 question please

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stressedparent
Posts: 126
Joined: Mon Jul 19, 2010 1:30 pm

Answer to a type 19 question please

Post by stressedparent »

help please with this question,it is driving me mad as neither I nor my daughter could solve it.

2 ( 9 ) 5 , 4 (21) 5 , 5 ( ? ) 2


Many thanks
stressedparent
Bewildered
Posts: 1806
Joined: Mon Feb 20, 2006 2:29 pm
Location: Berkshire

Re: Answer to a type 19 question please

Post by Bewildered »

stressedparent wrote:help please with this question,it is driving me mad as neither I nor my daughter could solve it.

2 ( 9 ) 5 , 4 (21) 5 , 5 ( ? ) 2


Many thanks
Only thing that makes sense is...

2 ( 9 ) 5 ........... 2x2=4 then add the 5 =9
4 (21) 5 ........... 4x4=16 then add the 5 =21
5 ( ? ) 2 ........... 5x5=25 then add the 2= 27

therefore answer... 5 ( 27 ) 2
Applepie
Posts: 18
Joined: Mon Dec 21, 2009 10:47 am
Location: Kent

Re: Answer to a type 19 question please

Post by Applepie »

hello I think it is

2 (9) 5 = 2x5-1

4 (21) 5 = 4 x 5 -1

therefore

5 ( 9) 2 = 5x2-1

Hope this is right all i can think of
Applepie
stressedparent
Posts: 126
Joined: Mon Jul 19, 2010 1:30 pm

Re: Answer to a type 19 question please

Post by stressedparent »

many thanks Bewildered I could see it now
stressedparent
patricia
Posts: 2803
Joined: Mon Jan 30, 2006 5:07 pm

Re: Answer to a type 19 question please

Post by patricia »

I would go for applepies method, as you must use the numbers either side of the brackets first.

Which publisher is this from? What was their answer?

Patricia
Tolstoy
Posts: 2755
Joined: Wed Aug 13, 2008 5:25 pm

Re: Answer to a type 19 question please

Post by Tolstoy »

Applepies method doesn't work as you would have to add 1 to get 21 not - 1.

- would have used Bewildereds method so am suprised to hear that it is incorrect.
patricia
Posts: 2803
Joined: Mon Jan 30, 2006 5:07 pm

Re: Answer to a type 19 question please

Post by patricia »

Quite right too!

Going back to my siesta...

Will take another look later. Not saying Bewildered is incorrect.

Would be interested in the publisher and their answer.

Patricia
rosered100

Re: Answer to a type 19 question please

Post by rosered100 »

I'd say bewildered's was correct as it does use the outside brackets first?

1. 2 squared +5 = 9
2. 4 squared + 5 = 21
3. 5 squared + 2 = 27
Amber
Posts: 8058
Joined: Thu Sep 24, 2009 11:59 am

Re: Answer to a type 19 question please

Post by Amber »

Didn't the book have the answer somewhere?
patricia
Posts: 2803
Joined: Mon Jan 30, 2006 5:07 pm

Re: Answer to a type 19 question please

Post by patricia »

I think Bewildereds method is probably the answer , however it does not use the known technique of using the numbers either side of the brackets in the first instance. [squaring one the numbers is "doing" something to one of the numbers before you start]

However...

Patricia
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