Zion has a rectangular commercial block with 13 offices lined inside, one after the other in a single row. Morpheus works in the 11th office. The only way to enter the office block is from the main gate near the first office (numbered 1). Since the distances between the offices are large, there is a metro service that connects all the offices. The metro is parallel to the office block and moves left (towards office 1) and right (towards office 13) continuously through offices 1, 2, 3,.., 12, 13,.., 5, 1, 3, ..., except that it stops at an office for which the card has been swiped. Assume that time spent entering and exiting the metro is very small compared to the time office goers spend travelling. Morpheus is a busy worker and complains that at 7pm, when he wants to go home (head to office 1, exit and then walk across to the residential side of Zion), the metro almost always goes right when it stops at his office. a) What is the explanation for this? b) Now assume that there are 5 such office blocks, with each having their own metro line that move independently. Compute the proportion of times the first metro at Morhpeus' office moves right.