There are 20 books on Algebra and Calculus in one library. For the greatest number of selections each of which consists of 5 books on each topic. If the possible number of Algebra books are N, then the value N/2 is __________.

There are 12 books on Algebra and Calculus in our library,the books of the same subject beingdifferent.If the number of selections each of which consists of 3books on each topic is greatest thenthe number of books of Algebra and Calculus in the library are respectively:

There are n different books and p copies of each in a library. Find the number of ways in which one or more than one books can be selected.

In a library, there are 10 different sections and the librarian categorises the books over 20 days. Which section has the least number of books?

There are m copies each ofn different books in a university library.The number of ways in which one or more than one book can be selected is

There are k different books and I copies of each in a college library. The number of ways in which a student can make a selection of one or more books is

A library has 6 copies of one book,4 copies of each of two books, 6 copies of each of three books and single copies of 8 books. The number of arrangements of all the books is