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.
[[17, -135], [-59, 30, 64], [52, -102, -151, 51, -168, 68, -21]]