1) During Math class Jim and John were playing 3x3 Tic Tac Toe. (On a 3x3 square grid two players place an X and an O sign alternating, each player having his own sign. The first person having 3 of his signs in a row, column or in a diagonal wins the game.) Upon noticing this activity, their Math teacher gave them the following penalty: They had to calculate how many different grid formations would give a simple victory to one of the players. (A simple victory means that the first 3 marks of a player make him a winner.) Two formations are considered to be the same if one formation can be moved into the other by rotation and/or reflection. If the numbers of X's and O's are different, then the formations are considered to be different.)
My son's answer is 87, is it correct?
My son's answer is 87, is it correct?