Re: 'Numbers of students' Vs. 'Number of students' -----which is corect to mean more than one s
Only plural "students" is correct because "number" means more than one. But "number" can be singular or plural depending on the intended meaning:
(1) A number of students have been found smoking.
(2) Huge numbers of students were found getting drunk all over town.
The meaning in (1) is that some students (more than one) were found smoking. But (2) implies that many large groups of students were found getting drunk in various places in town.