The grid of numbers with a row and column sum of 30 is
3   15  12
17   11   2 
10  4   16
<h3>How to prepare the grid?</h3>
The grid in the question has a row sum and column sum of 15
The question implies that we create a similar grid with a row sum and column sum of 30
Represent the grid as follows:
a    b   c
d    e    f
g   h    j
So, we have the following sum of rows
a + b + c = 30
d + e + f = 30
g + h + j = 30
And, we have the following sum of rows
a + d + g = 30
b + e + h = 30
c + f + j = 30
Using trial by error, we have:
3 + 15+ 12  = 30
17 + 11 + 2 = 30
10 + 4 + 16 = 30
When the columns are added, we have
3 + 17 + 10 = 30
15 + 11 + 4 = 30
12 + 2 + 16 = 30
Hence, the grid of numbers is
3   15  12
17   11   2 
10  4   16 
Read more about number grid at:
brainly.com/question/4727909
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