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.
[[-112, 75, -10, -77, 14, -139], [-1, -78, -187, -19, -128], [-9, 31, -134, 46], [50, 88, 86, -85], [74, -188, 36, -159, -73, -75], [-20, 50], [87, -75]]