How to answer these?

A 125-page document is being printed by five printers. Each page will be printed exactly once. (a) Suppose that there are no restrictions on how many pages a printer can print. How many ways are there for the 125 pages to be assigned to the five printers? One possible combination: printer A prints out pages 2-50, printer B prints out pages I and 51-60, printer C prints out 61-80 and 86-90, printer D prints out pages 81-85 and 91-100, and printer E prints out pages 101-125. (b) Suppose the first and the last page of the document must be printed in color, and only two printers are able to print in color. The two color print- ers can also print black and white. How many ways are there for the 125 pages to be assigned to the five printers? (c) Suppose that all the pages are black and white, but each group of 25 con- secutive pages (1-25, 26-50, 51-75, 76-100, 101-125) must be assigned to the same printer. Each printer can be assigned 0, 25, 50, 75, 100, or 125 pages to print. How many ways are there for the 125 pages to be assigned to the five printers