Skip to main content

LOGIC BEHIND MAGIC SQUARE

Assume a magic square of 3x3
A
B
C
D
E
F
G
H
I
The above figure shows a 3x3 magic square. In the magic square sum of colum, row, diagnol numbers should be same
A+B+C=D+E+F=G+H+I=A+D+G=B+E+H=C+F+I=A+E+I=C+E+G=sum
A+B+C
D+E+F
G+H+I
A+D+G
B+E+H
C+F+I
A+E+I
C+E+G
By  seeing the  above there is 8 type of sum is available. Row wise-3,  column wise-3, diagnol wise-2. Condition#1:
There are 8 different combinations are there with same sum in a magic square.
In the above 8 combinations A=2 times, B= 3 times, C= 2 times, D=3 times E=4 times, F=3 times, G=2 times, H=3 times, I= 2 times
Hence the above forms the condition#2. In simply condition#2, middle number E appears 4 times in 8 combinations.
Hence row, column, diagnol sum should be equal. In 3x3 magic square we are taking numbers from 1 to 9. From 9 numbers we need to take 3 numbers. From combination formula we can find out the the number of ways we can write
Combinations= 9c=84.
From 9 numbers by taking 3 numbers at a time we can form 84 combinations. All 84 combinations we are showing here.






1+2+3=6
2+3+4=9
3+4+5=12
4+5+6=15
5+6+7=18
6+7+8=21
7+8+9=24
1+2+4=7
2+3+5=10
3+4+6=13
4+5+7=16
5+6+8=19
6+7+9=22
(1)
1+2+5=8
2+3+6=11
3+4+7=14
4+5+8=17
5+6+9=20
6+8+9=23

1+2+6=9
2+3+7=12
3+4+8=15
4+5+9=18
5+7+8=20


1+2+7=10
2+3+8=13
3+4+9=16
4+6+7=17
5+7+9=21
(3)

1+2+8=11
2+3+9=14
3+5+6=14
4+6+8=18
5+8+9=22


1+2+9=12
2+4+5=11
3+5+7=15
4+6+9=19



1+3+4=8
2+4+6=12
3+5+8=16
4+7+8=19
(6)


1+3+5=9
2+4+7=13
3+5+9=17
4+7+9=20



1+3+6=10
2+4+8=14
3+6+7=16
4+8+9=21



1+3+7=11
2+4+9=15
3+6+8=17




1+3+8=12
2+5+6=13
3+6+9=18
(10)



1+3+9=13
2+5+7=14
3+7+8=18




1+4+5=10
2+5+8=15
3+7+9=19




1+4+6=11
2+5+9=16
3+8+9=20




1+4+7=12
2+6+7=15





1+4+8=13
2+6+8=16
(15)




1+4+9=14
2+6+9=17





1+5+6=12
2+7+8=17





1+5+7=13
2+7+9=18





1+5+8=14
2+8+9=19





1+5+9=15






1+6+7=14
(21)





1+6+8=15






1+6+9=16






1+7+8=16






1+7+9=17






1+8+9=18






(28)

Total 84 combinations

As you seen above table total combinations from 9 numbers by taking 3 numbers at a time is
28+21+15+10+6+3+1=84.
Now we will verify the sum of the combinations







Sum=6 combinations
1
Sum=7 combinations
1
Sum=8 combinations
2
Sum=9 combinations
3
Sum=10 combinations
4
Sum=11combinations
5
Sum=12 combinations
7
Sum=13combinations
7
Sum=14 combinations
8
Sum=15 combinations
8
Sum=16combinations
8
Sum=17 combinations
7
Sum=18 combinations
7
Sum=19 combinations
5
Sum=20 combinations
4
Sum=21 combinations
3
Sum=22 combinations
2
Sum=23 combinations
1
Sum=24 combinations
1
TOTAL
84 COMBINATION
By seeing the above table in SUM=14,SUM=15,SUM=16,  there are 8 combinations are available. So condition#1 is satisfied for sum=14, sum=15, sum=16. Since we will analyse the above 3 for condition#2. The following table analyses the condition#2.
Sum=14 combinaztions
Sum=15 combinaztions
Sum=16 combinations
1+4+9
1+5+9
4+5+7
1+5+8
1+6+9
3+4+9
1+6+7
2+4+9
3+5+8
2+3+9
2+5+8
3+6+7
2+4+8
2+6+7
2+5+9
2+5+7
3+4+8
2+6+8
3+4+7
3+5+7
1+6+9
3+5+6
4+5+6
1+7+8
In the above condition number#2 is satisfied for the sum=15. Since to prepare a magic square sum=15 combinations are suitable because 5 is appeared 4 times. Remaining combinations are not suitable. Now we can prepare the magic square with sum=15 combinations. The different combinations to prepare the magic square 1+5+9, 1+6+9, 2+4+9, 2+5+8, 2+6+7, 3+4+8, 3+5+7, 4+5+6. In this combinations 5 appeared 4 times. By using the above combinations the magic square is like follows.
4
9
2
 3
5
7
8
1
6
In the above magic square 3x3 we are used numbers from1 to 9 arranged in 9 boxes. In any direction the sum equal to 15.
Row wise  4+9+2=15, 3+5+7=15, 8+1+6=15.
Column wise 4+3+8=15, 9+5+1=15, 2+7+6=15.
Diagnol wise: 4+5+6=15, 2+5+8=15.
 



Comments

Post a Comment

Popular posts from this blog

Average of first n even numbers

Even numbers are 2,4,6,8,10,…. Average = sum of elements/ no of elments Now we will see the sum of elements: Sum of first 2 even numbers: 2+4= 6= 2(2+1) Sum of first 3 even numbers: 2+4+6= 12= 3(3+1) Sum of first 4 even  numbers: 2+4+6+8=20= 4(4+1) Sum of first 5 even numbers: 2+4+6+8+10 = 30 = 5(5+1) Sum of first n even numbers: 2+4+6+8+10+. . . . .  n numbers= n(n+1) Now we will see average: Average of first 2 even numbers= (2+4)/2                                                           = 6/2                              ...

product two consecutive odd numbers

Product of two consecutive odd numbers : Even numbers are 1,3,5,7,9,11,13,15,17,19,21,23,25,..... Odd  number means when we divide a number with 2,then the remainder is equal to one. Difference between the two odd numbers is 1. Now we will discuss the product of two odd  numbers. Now the product of two even numbers assumed to be 5x7 can be written as (6-1)x(6+1).                              5x7= (6-1)x(6+1) From the above we write general formula as 5x7= (6-1)x(6+1)=6 2 -1 2  =36-1=35 Now we can observe the result as one less than the square number. So now we can observe the following table. Column 1&2 reprecent the adjacent odd numbers. Column 3 represent the product of two adjacent odd numbers. Column 4 represent  the nearest square number. This  will arrive by adding 1 to the product  of two odd ...

MULTIPLICATION OF TWO CONSECUTIVE NUMBERS

If you observe the sum of each digit in the Multiplication of two consectuive no.  pattern repeating:  2 6 3  2 3 6 2 9 9  n X n+1 Multiplication of two consectuive no. Sum of two digits 1X2 2 2 2X3 6 6 3X4 12 3 4X5 20 2 5X6 30 3 6X7 42 6 7X8 56 2 8X9 72 9 9X10 90 9 10X11 110 2 11X12 132 6 12X13 156 3 13X14 182 2 14X15 210 3 15X16 240 6 16X17 272 2 17X18 306 9 18X19 342 9 19X20 380 2 20X21 420 6 21X22 462 3 22X23 506 2 23X24 552 3 24X25 600 6 25X26 650 2 26X27 702 9 27X28 ...