Given a grid with 15 sections, determine how many sections in the grid need to be shaded so the probability of a point chosen at random in the shaded area is exactly 0.8. explain your reasoning. the number of squares that are shaded divided by 15 must equal 0.8, so the number of squares must be 0.8(15), which equals 12. the fraction 12/15 reduces to 4/5 which is equal to 8/10.