一个100*100的正方形，用半径为10的圆覆盖，随机在100*100的平面内放置圆心，问至少需要多少个圆，才能使得成功覆盖整个区域的概率在95 以上？并给出一个均匀随机放置装置的分布图。-A 100* 100 square, a circle with a radius of 10 covers, 100* 100 randomly placed on the center plane, and asked how many circles at least, to cover the entire area so the probability of success of 95　or more? And gives a uniform distribution of randomly placed devices.