In a 3 x 3 grid, comprising 9 tiles can be painted in red or blue. When tile is Rotated by 180 degrees, there is no difference which can be spotted. How many Such possibilities are there?

• first we assign number to grid in this form
  1 2 3
  4 5 6
  7 8 9
  
  now,there r 2 ways(either red or blue) to fill position 1,but position 9 has 1ways(same color as in position 1)
  similarly position 2 has 2 ways & position 8 has 1 way
  similarly position 4 has 2 ways & position 6 has 1 way
  similarly position 7 has 2 ways & position 3 has 1 way
  & position 5 have 2 ways
  so total possibility=2*1*2*1*2*1*2*1*2=32
  ans is 32
  
  
• 11 years agoHelpfull: Yes(23) No(1)
• 2^5=32 possiblities
• 11 years agoHelpfull: Yes(11) No(4)
• 1 3 2
  4 5 4
  2 3 1
  This grid even rotated 180 degrees the relative positions of the tiles do not change. So we paint tile number 1's with red or blue (only one color should be used) , 2's with red or blue.....tile 5 red or blue. Then total possibilities are 25 = 32
• 11 years agoHelpfull: Yes(3) No(2)