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.
ANSWER: 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.