I think this has been solved before in this forum but cant find the link.


Her's how u can solve it using the rows(I think the column approach is alittle easier than this one but I tend to use rows than columns so here it goes)

If you notice the sum of first row is 28

Second row = 2 times the first row and all negative = -2(28) = -56

Third row = 3 times first row but and all positive = 3 (28)

Fourth row = 4 times the first row but all negative = -4(28)

Similarly we can do it for other rows...


If you add all 7 rows u get

1(28)-2(28)+3(28)-4(28)+5(28)-6(28)+7(28)

= 28 * (1-2+3-4+5-6+7)

= 28 * 4
= 112

think this has been solved before in this forum but cant find the link.


Here's how u can solve it using the rows(I think the column approach is a little easier than this one but I tend to use rows than columns so here it goes)

If you notice the sum of first row is 28

Second row = 2 times the first row and all negative = -2 ( 28 ) = -56

Third row = 3 times first row but and all positive = 3 ( 28 ) = 84

Fourth row = 4 times the first row but all negative = -4( 28 ) = -112

Similarly we can do it for other rows...


If you add all 7 rows u get

1( 28 ) - 2( 28 ) +3( 28 ) -4( 28 ) +5( 28 ) -6( 28 ) +7( 28 )

= 28 * (1-2+3-4+5-6+7)

= 28 * 4
= 112

cramya wrote:think this has been solved before in this forum but cant find the link.


Here's how u can solve it using the rows(I think the column approach is a little easier than this one but I tend to use rows than columns so here it goes)

How do you solve it the Column way?

One more way:

You can easily identify the pattern here:

First Column = 1 -2 + 3 - 4 + 5 - 6 + 7 = 4
Second Column = 2 - 4 + 6 - 8 + 10 - 12 + 15 = 8

The middle row is just the median of all values

sum the middle row = 4 + 8 + 12 + 16 + 20 + 24 + 28 = 112.

Hope this helps.