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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 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

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

many thanks Bewildered I could see it now

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

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.

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

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

Didn't the book have the answer somewhere?

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