a hiker begins hiking up a trail to the top of a mountain at 9am. on his hike his speed varies, sometimes moving faster or slower, but he always is moving forward up the trail. he reaches the top at 5pm where he camps for the night. the next morning at 9am he begins hiking down the trail. once again, his speed varies, sometimes moving faster or slower, but he always is moving forward down the trail. he reaches the bottom at 5pm. on his return trip, what is the probability that the hiker will be at exactly the same spot on the mountain at the same time of day as he was on the previous day's hike?