you are throwing darts at a square target with corners at (0,0)(0,0), and (1,1)(1,1). each dart lands uniformly over the target. let yy be the distance from the dart to the xx-axis, and similarly, xx be the distance from the dart to the yy-axis. let dd be the manhattan distance from dart to the origin, x yx y. What is the probability that D≤0.5? Express your answer as a fraction a/b in simplest form. What is the probability that 0.5≤D≤1? Express your answer as a fraction a/b in simplest form.