In a certain game of chance, a square board with area 1 is colored with sectors of either red or blue. a player, who cannot see the board, must specify a point on the board by giving an x-coordinate and a y-coordinate. the player wins the game if the specified point is in a blue sector. the game can be arranged with any number of red sectors, and the red sectors are designed so that 9 20 i ri        , where ri is the area of the th i red sector. calculate the minimum number of red sectors that makes the chance of a player winning less than 20%. (a) 3 (b) 4 (c) 5 (d) 6 (e) 7