Gnat prep -box

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Source: — Problem Solving |

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by California4jx » Mon Dec 15, 2008 6:42 pm
- Add 1st row and 2nd row ... you wil get back 1st row but in negative

- Add the resulting row with 3rd row -- you'll get back second row but with +ve sign

- Add the resulting row with 4th row -- will get back 2nd row with -ve sign

- Add resulting row with 5th - you'll get 3rd row

- Add resulting with 6th - you'll get 3rd row in -ve

- Add resulting with 7th - you'll get 4th row with +ve

- Add 4th row together: 112

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by vishubn » Mon Dec 15, 2008 6:45 pm
Many approaches have been discussed ! i rememebr ! one approach which i did when i saw the same problem !!

When u look at each row !! its in the form 1, 2 3 4 5 6 7 muliples !!

soooo it has to be form of some multiple of a number

so first row is 28 before i go to the second row calculation i know it will come with the number which will be arounda the principle of multiplicity

28
-56
so on....

x,-2x,3x,-4x,5x,-6x,7x=4x so x =28
there answer is 112

vishu
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by Abdulla » Mon Dec 15, 2008 9:17 pm
look at this..

Add the first row you will get 28
Add the first column you will get 4

28 (4) = 112 ..
Abdulla