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.
[[-136, -112, -117], [-9, 57, 77], [50, 85, -172, -187, -119, -156, -28], [20, 40]]