In this task, you are given a list. This list contains many lists of integers. The list is several items written within a []. Your task is to find the maximum number among the members of each inner list. The output should be a list comprised of the maximums with the same order as the internal lists.
[[-5, -4], [-45, 72, -120, 42, 8], [48, -61], [3, -142, -86, -172]]