There is a stack made of 6 squares. As you can see there are yellow squares between red ones. The question is what will be the next row like? And why?
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The answer is
Number 2 because the boxes represent binary values of the sequence of squares.
Red is 0
Yellow is 1
000001 1
000100 4
001001 9
010000 16
011001 25
100100 36
and now
110001 49